Cheap shirts for summer?

Old american apparel shirts have always worked fine for me. They dry out quick enough in Kentucky summers and are pretty comfortable. I think they want around $18 if you buy them at msrp, but a lot of bands and such buy them wholesale and sell them printed for $10. I've accumulated a ton over the years.

I've given up on "the fancy 50 dollar vented microfiber shirts" primarily because of the "funk" factor. I've switched to the thin polyblend you described in a regular LS dress shirt design. I look for 65 poly/35 cotton blend. I get them at Salvation Army, etc and never pay more than $2.

Eight years ago, I got a few polyester t-shirts from Walmart for around $10 each. They've held up well, and I still wear them. I haven't compared the moisture wicking, but they're more comfortable than the Nike DriFit t-shirt I paid at least twice as much for.

I agree with the poly/cotton blends.
Wool for winter, cotton blends for summer.
Poly/cotton is more comfortable, stinks less, and is affordable. Not to mention that you can get normal good looking clothes in those materials to hike in without racing stripes and the long sleeve button ups don't make you look like the dorky professor on an archeological dig like the expensive synthetics at the outfitters.
None of my old expensive super technical synthetics see much use. I wouldn't wear them at all but I might as well wear them out rather than throw them out. Won't waste my money again.