Discuss the various aspects of heat press technology. Transfer paper, inks, plastisol transfers, vinyl cutters, printers, commercial usage, durability, suppliers, etc.
I come up with 13.40 each for something like that myself. I think screen printing for those low numbers will kill it. This would be for a local customer that I wanted repeat business from as well.
The key that you have are the names imo. That allows you to charge much more then a normal screen print due to being custom and low quantity.
Take the cost of the t-shirt X 2 (or 2.5), and add a buck for your in-bound shipping.
Calculate the cost of the vinyl you will need for each t-shirt. Remember, calculate by the size piece you need to cut the design, not the final design size (example: you need a piece larger than 12X12 to cut that 12X12 design). I would calculate the back separately from the front, because you'll likely cut all the backs, then cut all the small front designs on one large piece. Think in terms of square inches here.
Once you have your cost of vinyl, and your shirt with mark-up, then add in your labor (cutting & pressing time) to get the final price.
Since all the shirts will have the same back, and you have 40 of them, and it's just one color, I would also advise that you look into plastisol transfers for the back. It will save you a lot of time by not having to cut and weed...cost wise, it may be the same or cheaper than vinyl. And after all, time is money.
I would use vinyl for the front and plastisol for the back.I would advise you to get a cost estimator from www.heatpressvinyl.com this allows you to figure your truly calculate your cost quick.I would be in the $12 - $14 dollar each range depending on the weeding of the vinyl. I also figure a minimum of $1 for each press too. ... JB
40 shirt order, what would you charge? 
