Agreed, I'd look a bit harder for clothing that has no cotton in it. I've done some hard walking in clothing that's a mix of cotton and synthetics and it still has some of the downsides of cotton.

A common piece of advice people often get is to shop at thrift stores for backpacking clothing, and just look for synthetic stuff, but indeed sometimes it can be hard to find stuff that doesn't have some cotton in it. You can instead look for sales on no-cotton clothing from actual outfitter stores, such as http://spadout.com/, http://www.sierratradingpost.com/, or http://www.rei.com/outlet.