Reddit reviews MJ Soffe Men's Long-Sleeve Cotton T-Shirt, Black, X-Large

https://www.amazon.com/dp/B003AU5WC8/ref=cm_sw_r_other_apa_QTVLxbP5CGAQR

Actually $8 in most sizes and $7 in small from Amazon Prime. There are some sweet other colors too. I'm 6'2 and got an XL, fits well.

Throw together a Klingon get-up, but don't take yourself too seriously. A plain undershirt under some armor, a wide belt, a silver sash, some brown knickers, some knee high equestrian boots or wading boots, find some black leather gloves and/or gauntlets if you want, get a brown bald curly clown wig and strap one of these to your head with a rubber band, voila.