Lisa, I am in the process of making a T shirt quilt. I told the client $10 a block. I am also keeping track of how many hours I spend, cutting, fusing, blocking sewing etc. etc. as well as receits for the backing, batting, sashing and stabilizer. That way I can show them the real bargin they are getting. So far I have 15.5 hours and $55 in materials in it that I got on sale with coupons. I expect there is probably another 20 hours worth of labor coming. I figure they are getting it for a little over minimum wage. I didn't include my thread and the power used to run my equipment in the breakdown.
I hope they don't find friends that want the same thing.