I have issue spending money in RPG's. I rarly upgrade my weapons or buy thing unless its status effect ailments and whatnot.
I never upgrade my armor or weapons unless I see a +14 or more increase in Attack or something close to it.
I only bought 2 swords and I'm past your part :/ and I think I bought one of those 2 to alchemy something <
Yah there's at the same time an incentive to buy and an inventive not to buy I think they should increase the resell value of items or sth in jrpgs. Usually I am able to resist but in this one I splurge to upgrade the equipment of my creatures for pretty much all the ones in my party at every city I visit, then I get quite frustrated when during a quest I run into an item I just bought then have to resell it for less than half the price sigh.