I like minimus.biz for small, individual samples of items that can spoil quickly if opened and not completely consumed.

While this is off-topic for this query, I might mention if someone lives alone or as a couple, huge size cans work poorly if the contents aren't eaten in a single serving and can't be refrigerated after opening. Minimus.biz offers lots of single-serving sizes to prevent such spoilage.

Which brings me back to topic - tylenol, motrin, and the like have a shelf-life. Insect repellant, band-aids, and the like either don't or the shelf-life is so long it won't matter.

Costco sells a box of 280 assorted band-aids for $12; Tylenol is $15 for a bottle of 325 capsules. I'd expect my local drugstore to have big bottles of its private-label brand of OTC stuff on the shelves, although I haven't checked. Sometimes shipping eats any online savings, so I often compare online price, tax, and shipping to the local price and tax. Check your newspaper for circulars - our local drug store often has sales offering 2 for 1 pricing. (Example, the store brand acetaminophin is regularly $9 for a hundred tablets; on sale now for $4. So $12 gets you 300 instead of Costco's 325, but no shipping cost.)

I'd be interested in knowing the life of a bottle of NSAIDs before opening and after opening. There may be none, but the rotation schedule for the unopened bottle can be set. If the difference is significant, I may want to consider having several smaller bottles instead of one big one.