Except this opinion is based on metagame considerations. Not everyone has access to exactly the magic items they want any time they might have the gold to buy them. Many DMs have a different take on things and don't just let you wander down to the local Ye Olde Wal*Marte and clean out the magitech isle.
A few thousand gold? Our 7th level group *might* be able to scrape that up between all of them if they pooled everything, but I doubt it. Massive piles of cash don't make much sense in most situations despite what books might say, and we rarely find them. Not every game lets you play e-bay for just the right combo of magic items.