Both of them are more expensive than pure cotton but doing the better job of wicking away moisture so you won't look like you just fell in the pool.
50-50 is essentially half plastic dude.
Tencel, which is actually made from eucalyptus fibers is great. And bamboo is also great. You can Google tencel or eucalyptus fabric shirts or bamboo shirts. I have several pairs of socks in these fabrics.
Both also make for awesome sheets. I only sleep on eucalyptus sheets. I can sleep on a thing I want. Only that for me. If you want more info PM me.
Neither are the same cost as cotton, the fabric is more expensive, but they are better in every way.
Trust me Old School Gator............I know what is up here..........I know what I'm talking about.