Dead simple alteration if you own a sewing machine. You simply sew a new side seam to take in what you want, cut off the old seam if desired, or leave it there if it doesn't bother you (it's all inside the shirt). Works on pants legs too, if you want to turn baggy clown-pants into something more fitted. learn to do this for yourself, it's a stupidly simply skill that will do nothing but save you money. Shit, you don't even have to Own a sewing machine, some community centers have them free to use, or get over on patternreview and see if there's someone local who's willing to help/donate an old machine to you.