most places are going to require a
minimum of 2,500 pieces @ approx $4-5 a piece...this is for some "basic" cut & sew and minimums are higher for more advanced techniques
thats just for the RAW shirts - you still need to have them dyed & treated, which is going to add another few thousand dollars
so you'd be looking at about $15,000+ and thats NOT including your printing
say it costs you about $6 a shirt to print (your designs have the possibility of being very involved) and mulitiply that by 2,500...there are places that print this type of stuff, some you dont even see listed or talked about on these forums - but these are not places you go in looking to print 144 shirts, they require you to print thousands of shirts a month to even have them consider working with you
you'll be at about $30,000 just for your materials - now factor in your marketing budget on top of that & things get expensive very quickly
you might wanna give Beau (Bare App.) another look, until you get your brand established & are ready to make that kind of jump