I really like to incorporate the ABP system into a newish campaign, but ran into a bit of trouble with the system.
I took over an ongoing AP. Now that we finished book 4, I thought it would be a good time to switch over to the ABP and, as the previous DM was not that caring, normalize the wealth.
So, as the PC's are now 13th level, they all get to re-purchase equipment to a total of 70.000gp, but we aren't exactly sure how much some things are worth.
Take for example our fighter that just found a +1 medium fortification full plate. That normally costs 1500gp (full plate) + 150gp (masterwork) + 16000gp (+4 equivalent) for a total of 17650gp.
To price a similar item under ABP I quote this:
In this system, adding bonus-equivalent special abilities to items costs significantly less because you are paying only for the special ability, not for a base enhancement bonus (see the table below). To determine the price of specific weapons and armor, remove the flat enhancement bonus and reduce the item's cost by the amount listed on the table below. For example, a flame tongue is normally worth 20,715 gp, but under this system, it would lose its +1 enhancement bonus and its price would be reduced to 18,715 gp. Specific weapons and armor can be attuned; they then grant the character's enhancement bonuses from weapon attunement and armor attunement as normal.
So, the usual costs of the base armor and masterwork still apply, but here comes the question:Does the fighter pay for the +3 equivalent of medium fortification 9000gp, or (according to the second sentence there) 15000gp (16000gp - 1000gp)?
To determine the price of specific weapons and armor, remove the flat enhancement bonus and reduce the item's cost by the amount listed on the table below.
just apply to specific weapons and armor?
A bit late to this but to clarify: You're mixing the specific magic item rules and general magic item rules. For a specific magic item you just remove the gold price equivalent to it's enhancement bonus, so you get Milo's answer. Seems to me this would end up making specific magic items a little more expensive than their generic equivalents.
However, in the case of a generic Full Plate with Medium Fortification you get the 10,650 cost as you are only paying for a +3 bonus instead of a +4.
It'd be important to remember also that at lvl 13 they're only at a +2 armor attunement bonus, which means they wouldn't have anything left after they subtract the enhancement bonus of Medium Fortification (but won't inflict a penalty).