In short, the answer is "no."
In long, there are actually a handful of things you can evaluate.
First of all, money is a terrible indicator. It tells you nothing. I've had weapons worth a 10th as much as others that were OBVIOUSLY better. I think money is calculated based on part levels and rarity, but those often mean quite little in the latter part of the game.
While it seems like it can be easy to calculate DPS of weapons, it can often be hard as reload speed can often factor in quite a bit. For example, I once had a weapon with only a two round magazine with a high damage and wanted to compare it to a weapon with a slighter lower damage output but a much larger clip. Well, since I was playing a hunter, I had lots of points put into my pistol re-load speed, so it made it really hard to figure it out.
What I did then, was fire each of them continuously for a set period of time (say 20 seconds) and count the number of times each of them fires. This then factors in your reload speed as well. Then, simply figure out how much damage each shot does (multiplying for shotguns if necessary) then divide by time. I determined that even though I was reloading VERY frequently with the smaller magazine revolver, it's damage output was a full 33% higher than the other gun.
While this strategy works great for guns without elemental effects, it's a lot more challenging when it comes time to compare elemental damages. As a basic rule of thumb, compare apples to apples, i.e. compare fire to fire and so forth. x4 beats x3, etc, so that's often easy to figure out. You also generally want to try to have at least a fire and a corrosive gun on you at all times, and hopefully an electricity gun at all time. So when you are comparing, compare specific elemental slots to each other.
There are a few factors that you can't count for, such as zoom factor. Some people like zoom, other don't. It's worth something different to everyone, so give it as much weight as you want. Magazine size, bullet count, and damage can all be used to calculate overall DPS as I listed above.
Finally, learn what the special effects on the rare weapons do. There's a great list here:
http://borderlands.wikia.com/wiki/Special_Weapon_Effects
Some of the effects are pointless, only affecting things like the spread of the bullets, meaning that you could easily find a purple or even a blue better than said orange. Other effects significantly increase the damage of the element or something similar, so be sure you know what you have.
There's nothing clear cut, but you can do pretty well most of the time. Finally, there's no accounting for tastes/real world experience. If you can't decide which is better, carry both for a while and see which one feels most awesome. Use that one.
Melee off Piss Wash Gully (Earliest opportunity)
If you have a partner Melee your vehicle while you're in it on the Piss Wash ramp, that also unlocks it. (Youtube Video)
Dahl Headlands
I've gotten it in the Dahl Headlands off the beginning Ramp. You've got to be lined up perfectly.
Rust Commons East
There's a bridge near the Middle of Nowhere that (at one point) during the game is lowered for you (I believe it's on the mission to go to Janistown); If you talk to the Claptrap, and then back up the racer, you'll get insane air if you jump the bridge while it's about 50 degrees or better.
General Knoxx's Armory
The highways in the Sunken Sea provide good opportunities. The easiest way to do it is to get in the racer and launch your self off the left end of a broken road (where the curb hits the road). The hitting of the curb makes you go higher and makes it more likely.
Best Answer
Aside from altering the game files and modded items, there is a way to get an indefinite amount of skill-points. It is via the character switch glitch.
"The character-switch glitch
"A becomes B."
Nomenclature:
CSG, A.K.A. the max/infinite skill-points glitch and the backpack-space/storage glitch. Infinite skill-points is a misnomer; it isn't infinite, it's indefinite.
Instructions:
To do the glitch, open the Select Character menu as the host starts the game. The glitch has been performed successfully when the Select Character menu is open after characters spawn. The earliest way to tell if the glitch has been performed successfully is if the Select Character menu is seen or heard to open before the loading screen.
Co-ordination:
Without controlling two accounts at the same time, the CSG is usually done by having the host count down to starting the game and the glitcher presses Select Character as they start. OnLive voice chat has a one-second delay, Skype doesn't. Using a recording to count-down helps to keep consistent timing; think "Non, je ne regrette rien" by Édith Piaf in Inception. It is better to be early than late when pressing Select Character: Pressing too late means waiting for the game to load and then having to rehost. Pressing too early means that the game doesn’t start and the glitch can be retried in seconds. An efficient signal-code: Have readying up in the lobby mean being ready for the count-down to CSG.
Mechanism:
The character picked in-lobby gets from the character picked post-spawn the following data: name, level (not including XP), and missions data. Nothing else changes. The CSG is character-class blind and doesn’t change items, weapons proficiencies, nor the character picked post-spawn. It may be best to CSG firstly to back up character data. CSGing to a higher-level character causes levelling up which awards skill-points etc.. Signing back in may be required to trigger this. If you have too many skill-points, the counter will glitch and only a certain number of points may be assigned. To be able to assign the rest, switch to a different character menu tab or exit the menu (unconfirmed). After CSGing from level one to 69 back to one, CSGing to level 69 does not reward any more skill points and I do not know why. What happens when CSGing from a higher-level to a lower-level is that the character will deal the damage of the new, lower level, but whatever was equipped before will stay equipped even if the Level Requirement is now too high. The character levels back up to their original level, as determined by their XP, the next time that they sign in.
CSGing to have completed DLC4 ("Claptrap's New Robot Revolution") seems to award its skill-points somewhat retroactively. Playthrough two is not unlocked until the Destroyer is defeated. Even CSGing to a character with pt. 2 unlocked does not unlock it on the switchee. CSGing from level one to a 69 with mission progress in pt. 2 then CSGing back to fresh does not unlock playthrough two.
F.A.Q.:
“Okay, I’ve got the character selection menu open. What do I do now? Who do I pick?” Depends upon what is desired.
“I want more backpack space.” A character that can still do the Claptrap Rescue missions must be picked. The explanation-paragraph of what the CSG does answers your question.
“OK, I picked a new character so I can go through the game again and do the Claptrap Rescue missions.” I hope you were careful against story-blocks in your decision. Don’t forget that you might want to change your name then have it save before or as you leave.
“Hey, the character that I picked in the lobby was level 69 but I’m level one now.” The next time that that character signs in, they will level up by their XP.
“OK, I CSGed my level 69 to a new character. How do I get more backpack space?” Rescue CL4P-TPs.
Dangers:
You won't hear ECHO comms that you've heard before. This seems to result in...
Story-blockage:
If a character, who has progressed beyond story-blocks points, is CSGed back to behind any story-block point, they will be story-blocked when they re-encounter them. The story-block points are that:
Those are the story-blocks at the beginning of the game. Near the end of the game, the story-blocks are that:
Too many weapon slots:
By regressing to a point where a mission that awards a Weapon Equip Slot SDU is undone, completing such a mission can award Weapon Equip Slots above four. Such slots are unseen in the inventory menu. Switching to a weapon in a >4th (greater-than-fourth) slot is done by scrolling to it. Anything equipped in a >4th slot is unequipped next sign-in. There seems to be no limit to the amount of >4th slots that can be gained.
Special thanks to HolyCrap-_-Lmao who brought the glitch to OnLive."