Why is it less video gamish to toss your weapon every few levels to get one more in line with what you need than to have your fathers sword have enchantments lain upon it?
The problem with hard to find components is that it discourages the PCs from doing it! As an old timer (well, relatively) I was nervous about allowing the PCs to freely buy, sell, and construct magic items myself. Having taken the plunge I now love this way of doing things. It gives me much less to think about.
For example - lets say my bad guy uses a bastard sword. No one in the group uses this kind of weapon. With standard 3e, they can sell it (at a loss, I might add) and get a weapon that is more appropriate.
Furthur, I don't worry about damage reduction and such. If you are tenth level and can't hit the critter than has DR 20/+3 because you blew your cash on a keen flaming sword of shock, that isn't my fault.
Also as far as buying items, except the most common items (+1 swords/daggers, wands of healing, etc) this means having them commissioned. This could take time that the PCs don't have, or prove to be difficult to find such a person. If a character in the group is making the items, there is XP drain to keep it under control.
Don't be afraid to let them outfit their characters as they see fit!