How about not distributing these items by the cartload when you are the DM ?
There's still (1) magic shops and (2) easy item creation, though. Few Wizards will refrain from creating an INT-boosting item.
and for any item above 5000 gp in market value, if a caster creates it he loses 1 constitution point permanently.
Are there magic shops, really? That'd be the main point. Magic items are meant to be gained during adventures, not bought in a magic wal-mart.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.