The MiC guideline also has this clause on the preceding page. MiC 231:

That's not to say you can't apply occasional constraints to how and when magic items can be purchased, only that the constraints should be reasonable and shouldn't prevent players from equipping their characters fairly. For instance, a character seeking a magic item should be in a community whose gold piece limit is equal or greater to the cost of the desired item. You might also choose to limit particular items for campaign story reasons - maybe the knowledge of how to create certain items is a closely guarded secret of a particular group, or even forgotten to all.
Using the bolded sentence, you can easily allow a bazaar of magical gear, but ban specific problematic items like Dust of Sneezing/Choking and Candles. Just come up with a campaign story reason (such as, say, an efreet in the distant past tricked another mortal into wishing for the Candles to be nearly impossible to find precisely to stymie shenanigans such as this) and you're justified.