We used to have some Polo shirts and we did a limited run of T shirts too - however the place that did the embroidery and drop shipping went bust. I looked for another company that could make and ship for a reasonable cost but never found anywhere. Add to that the fact that some went missing which I had to chase, people didn't always like the fit, people preferred a different logo etc etc... all quite a mission at the end of the day. There was zero profit, too.
If you've got a permanent marker and a plain T shirt then help yourself, you have my permission