Found my leather jacket at the swap meet. Warm shirts at the thrift store. I'm cheap. I like old stuff 'cause I'm old. I ride an '87 Softail Custom. Sweeeeet.
....an' I remember when Levi's were either blue ($3.75) or white ($4.75).
For cheap hot weather gear, look for a nylon shooting vest, the kind that has the big "game pocket" in the back. When the temps get up around a ton, you get a couple of big ziplock bags, fill 'em with ice, and stick them back in that game pocket and snuggle 'em up right over your kidneys.
I'm 5'1" and built like a Sherman Tank. I can't find anything 2nd hand. Sigh....