wow! 25000 in sales! I generally make about $1000 or more a month. My markup yields 25% so when when I sell a tee for $34 I make about $8 before merchant fees taxes and promotion. In the end it's like $4 bucks a shirt.
Print on demand can be more expensive sometimes so I'd recommend you find a manufacturer with a low moq of like 20-30 and do a mini-bulk. That's what I did for my first drop - or you can always run a preorder but that comes with its own risks. I'll be making a video about how to properly run a pre-order soon.