I’ve always found the idea of purchasing magical items boring. As a player I’d rather my character risk life and limb to battle monsters and delve into dangerous catacombs in hope of finding a special magical item. However, the reality is that I usually only find one or maybe two items this way. In order to fill out the rest of my PC’s inventory I usually end up purchasing the majority of his gear. This is the way D&D works.
As PCs advance and level up they’re eventually going to accumulate vast wealth. It’s an unavoidable reality. With this abundance of gold pieces comes the inevitable request to purchase magical items. PCs many not be able to purchase magic items in the middle of a dungeon crawl, but as soon as they hit a larger metropolis there’s few excuses for why they can’t convert their hard gotten gains into something more functional and portable.