depends on the t-shirt. a regular t-shirt, yeah you can get for ten buck easily. a designer one can run you whatever. I think the most expensive t-shirt i bought was like 40 bucks. the sad part is that was back in HS. now I buy the $5-$10 ones
I get most of my T-shirts for free these days. Freebies as promotions in my industry. Everybody whores themselves out on their own T-shirts pretty much, and I wear them only as they were originally designed: undershirts to real shirts, so I really don't pimp out the advertising company anyway.
Back home I've got a drawer full of T-shirts that my wife calls the "dead dot-com" drawer.
It's freaking underwear you're pretending to be actual clothes, dude.
Would it kill you to show a little self-respect and wear something with an actual collar now and then? A T-shirt is basically giving up. Put on the Crocs and sweatpants and eat at Applebees the rest of your life.