These bowls originated from an obscure prime - where the clerics and mages would work together to insure the protection of their temples, and the homes of the wealthy. Business men would invest in these objects to protect their dealings, giving themselves a 'safe' place secured from outside interference.
A demon bowl is a carefully crafted piece of pottery - roughly one foot in diameter at the rim. The bowls are often more shallow than they are wide, and sturdily built. What separates a demon bowl from any other sort of simple piece of tableware is the carefully written enscriptions around the inner surfaces of the bowl. Spiraling down into the depths of the bowl are words of binding, and protection - all centering around a central glyph of binding often featuring a picture of a demon bound in chains.
A demon bowl has the ability to capture and contain a fiendish being that comes within a certain radius of it. The fiend will be drawn into the bowl (appearing to be sucked into it in the form of dark smoke). The fiend's abilities are then severely limited by its containment. The demonic containment can be broken with a disjunction spell. Or supressed by antimagic or a dispel magic check. The containment can be easily destroyed by simply breaking the bowl as well. A demon bowl may contain only one fiend at a time.
When a full blooded fiend comes within 60 ft of the bowl it must make a will save (DC 20) or be contained by the bowl. If it makes the save, the fiend is considered shaken. This is due to the constant distraction of resisting the bowl's pull. A fiend only needs to make this save when it is first brought within the radius of the item - continued exposure does not result in further saves.
A contained fiend is able to communicate telepathically with those around it. All other special abilities are suppressed by the containment. It is not able to move or physically speak.
Bowls may be used in conjunction - by sealing one bowl over the top of another like a lid. A pair of bowls used in this way will amplify their power, increasing the will save to resist capture to a DC 45. If the bowls are unsealed, the contained fiend recieves a second will save at a DC 20 to escape containment immediately.
Type Wonderous Item
Market Value: 60,000
Craft Level: 12
Craft Prerequisites:
Creation Cost: 40,000
Weight :3 lb
I'm looking for some advice with the last little bit of this entry. The information for pricing, construction, caster level and the like. Bonus points to anyone who recognizes the source of this concept.
I know how easy it is to skim through things 
well, first of all, you need to say you need craft wonderous item, then you need to make a group of spells that could create that effect when combined, other than that, the only other thing i could say is, you need to make it a little more pricey, it is, after all, very powerful. other than that, they're cool