I would like 99 of these, and 99 of those, and 99 tents to pitch at the hottie.

I actually don't buy any healing items in most games, since you can usually find them in chests, closets, cupboards, or off of dead enemies. An exception is tents in most of the FF games, which I will buy ten or so and then restock then when I drop below 4.

As far as armor and weapons go, I will usually keep my primary party members' weapons as up to date as possible, and will buy armor upgrades either as necessary or when something that increases my defense significantly becomes available. I am not going to spent 15 - 20% of my total cash on a piece of armor that increases my defense by less than 5% or something. For my characters who aren't active combatants, I will upgrade their weapons maybe every other town if I have the spare currency.

Jam it back in, in the dark.