In app purchase limit of non consumable object available ?

Hundreds if not thousands. But you might be better off creating a consumable currency and using that currency to purchase items from a list. The user ourchases a bag of "10 Tokens" and then uses those tokens to but one widget (for 2 tokens) and 3 wadgets (for 1 token each). You separately present the list of widgets and wadgets and other products available in exchange for Tokens.