[RPG] Are there rules for drowning in 4e

You go up a level at the moment you gain the requisite amount of experience, no matter when the experience is given. The real question is when the Game Master actually gives out the experience. I've seen everything from after every encounter, to after each session (the most common from what I've seen), to after an adventure is complete.

So the bottom line is that you don't need to rest, but if you're GM wants to play the game that way, then that's the way it is (e.g. he's only going to give out the experience after an extended rest).

This is explicitly outlined in DMG 1 on page 121:

XP Per Encounter

Some DMs prefer to give XP after every encounter. ... Others prefer to award XP when the characters stop for an extended rest or at the end of a gaming session. It's purely a matter of personal preference but be mindful of the pace of the session. Don't stop to give out XP if it's going to bring the game to a halt at a tense moment.

Leveling Up

Soem DMs let characters gain the benefits of a new level as soon as they ahve the required XP to reach that level, while others prefer to wait until the characters take an extended rest or even until the end of a session before letting characters level up. That decision is entirely up to you (the DM). ... If leveling up would shatter the pace of the session, put it off until they take an extended rest at least.

The general 4e assumption is that mundane (non-magic) items are either not sold at all, or are sold at 20% of value. So you could theoretically fiat that the tunic cannot be sold. However, lets think about this loosely within the confines of the game's mechanics.

Ask yourself the following questions

• If this were a magic item, what level, rarity and type would it be (by type I mean major item or consumable).
• What mundane items resemble this item

If you can answer the first question then this should give you your answer fairly quickly, price them at a level that is appropriate for the powers they grant (that tunic is actually fairly close to the existing camouflage clothing that costs 30 gp, although of slightly less value, so price it below that).

The ore is a bit trickier. My suggestion would be that you have them find a smith or refiner to haggle with Have an idea in mind of what the value is and start the Smith's price lower and have them use their cha based skills to try to get him up. Settle at or around your target value (tweaking for rolls obviously).

Finally, because I just thought of it, Mordekainen's magnificent emporium brought in some new mechanics for trade goods that give some help to DMs for players looking to sell goods. It might not fit exactly but it could be helpful for setting some base lines.

Buying and Selling: To perform either of these transactions, establish the total value of the trade goods in question. Use the major purchase column on the table in the Pocket Change entry to figure out the level of this transaction. For example, unloading a rare book worth 10,000 gp—or a forged copy of the same—would be a 15th-level transaction. Use this information with the Difficulty Class by Level table (Rules Compendium, page 126) to determine the DC to sell or buy a trade good, or to recognize or pass off a fake item.