[Eric from NC]

Dick's Sporting goods might be a good place to look. They really get in a lot of local team stuff, although they don't really advertise it. I live in NC so its more NFL Panthers, Duke, UNC than Reds. They also get in a bunch of the championship T-Shirts day after Final Four and Super Bowl.

The MLB website has a terrible return policy. They won't even pay to ship the replacement item if it does not fit like every other online retailer does.