Q 185 I really suck at this whole math thing for creating items.
Customary location, 3rd level spell, 6th lvl caster, Divide by (5 divided by charges per day--only 1/day), activation is swift/free. How much?
A 185: Swift/free activation does not have a preset price to my knowledge, so any pricing scheme for it would be ad hoc. When replicating spell effects being made swift, I'd suggest pricing it as a spell 4 levels higher (ie: Quickened) and possibly with an increased minimum caster level to go with it.
Level 3, CL 6, 1/day, normal: 3*6*1800*1/5 = 6480g
Level 7, CL 6, 1/day, ad hoc #1: 7*6*1800/5 = 15120g
Level 7, CL 13, 1/day, ad hoc #2: 7*13*1800/5 = 32760g
Its price should probably be somewhere in that range, depending on the effect in question.