I have finished the first set, they are missing the knee pads, but other than that, they have everything for a Boba Fett. 
I sent the first set out for "proofing" and used a 9x13 inch envelope. It's what I use for sending plans here all of the time.
As far as cost, that is still up in the air. Between the cost of the paper, postage, and envelopes (along with the number of people wanting them already - 10) its not going to be as easy/inexpensive as I thought. I'll do the math and get a number by noon EST.
Darren