can a spell that gives a resistance bonus work in conjunction with an item that gives a resistance bonus? Or for that matter could the Bull's Strength spell work in conjunction with a Belt of Giant Strength? Would the spells be considered temporary bonuses?
If a character made the 0 level spell RESISTANCE permanent on himself would he still be able to benefit from a ROBE OF THE ARCHMAGI'S resistance bonus? And if so, would it stack?
Also, the cost of permanency makes that cost ineffective - 0th and 1st level spells cost 2,500 gp to make permanent while item granting the same +1 resistance bonus to saves costs 1,000 gp when made as a cloak or 2,000 if occupying no slot.
Do note that the character would still benefit from the Robe of the Archmagi because the resistance bonus is higher. When bonuses conflict, you use the higher one. But yeah, permanent or not, they won't stack.