As someone who makes a fair amount of shirts in the UK, I can tell you they'll be breaking even unless it's an exceptionally expensive fabric. It costs my brand £47 a shirt with relatively expensive fabric and I don't own my own factory!
It depends on the factory but we use a place called Tower Garments in Enfield and the minimum order quantities are fairly low. We're making c.2k shirts a year now but the price was pretty much the same when we were making batches of 100 shirts.
As someone who makes a fair amount of shirts in the UK, I can tell you they'll be breaking even unless it's an exceptionally expensive fabric. It costs my brand £47 a shirt with relatively expensive fabric and I don't own my own factory!