[RPG] Scroll Creation Pricing

Let's begin assuming you are casting off of a "scroll" in the form of a spell-scar. From the SRD:

The magus can use special scar-based tattoos called spell-scars on his skin to cast or prepare spells, much like scrolls. He can cast a spell from a spell-scar exactly like casting from a scroll; the ink and scars vanish when the spell is cast. The magus can also prepare spells from his spell-scars without expending them, similar to a wizard using the Spell Mastery feat.

The magus does not need to be able to see his spell-scar to use it. A magus has room on his skin for 18 total spell levels of spell-scars, which he can create using the rules for scribing scrolls (although they do not require the Scribe Scroll feat).

In this instance the "scroll" should be able to be used with spell-combat as it leaves your hand free for spell combat and it functions as casting a spell (see the sources cited in the question). I would note that while activating a scroll is a standard action, spell combat works with standard action spells (that being the whole point). Further from an RAI perspective it would be odd for this arcana (being a class feature of the magus) to not function with the primary feature of magi (Spell Combat).

Now let's assume that you are using a more traditional scroll and you can draw it as a swift action via some method (spring-loaded sheaths, being a tiefling, etc) or already have it drawn (because you theoretically could I suppose). Your hand is not precisely "free" but I would argue you can use spell combat anyway because of the existence of the Wand Wielder arcana which reads:

The magus can activate a wand or staff in place of casting a spell when using spell combat.

Two items of note:

• An interpretation of the word "free" in several other answers implies the hand must be empty as opposed to free to cast the spell. This interpretation would render Wand Wielder useless as an arcana and so we can assume that "free to cast the spell" is the correct interpretation, in which case casting off of a scroll should still be fine.
• There is no Scroll Wielder arcana. This is purely an RAI argument but one would assume there would be a Scroll Wielder arcana if scrolls didn't already work with spell combat.

tl;dr You should be able to cast from a scroll using spell combat assuming you didn't need to use a move action to draw it and that the spell is on your magus spell list.

You are looking at this?

Use-activated or continuous | Spell level × caster level × 2,000 gp²

The ² is a reference to footnote 2 - not a mathematical squared notation. (Of course, if it did mean squared [which it doesn't] then order of operations means you only square the 2,000).

² If a continuous item has an effect based on a spell with a duration measured in rounds, multiply the cost by 4. If the duration of the spell is 1 minute/level, multiply the cost by 2, and if the duration is 10 minutes/level, multiply the cost by 1.5. If the spell has a 24-hour duration or greater, divide the cost in half.

So the spell level is 5, the caster level is 9 (because you would create this at the lowest level needed to cast 5th level spells) giving \$5 \times 9 \times 2,000 = 90,000\$gp and, because the spells' duration is greater than 24 hours, you divide this in half giving \$45,000\$gp. The DC is 14.