I work for a large printing company and we do quite a bit of shirts too. Unfortunately we are more set up for longer runs and not short runs.
You need to find someone who does "direct to garment printing" (google that term in MD) for full color short run shirts (sort of like a laser printer for tee shirts). We have a machine we use but our minimums are like 24 pieces on it. Unfortunately for 2 sides you are looking like $22 a shirt at that quantity too for 2 sided with us. I am sure a mom and pop shop with smaller equipment can do better.
Now if you had a long run and wanted to sell them on line, I am your guy! I think you ought to get a couple thousand at a pop!
(we typically get competitive at 12 dozen plus)