I have found if I use anything with even a bit of poly (poly blend fabric or a batting with poly) I get sticking issues, but if everything is all cotton I will only use 505 or the Hobbs fusible batting, have gotten great results with both. I did a quick google search and the best price on the 505 I could find is 15.42 (dont know shipping, I think I have to actually go to check-out to see the shipping quote), here is the link
http://www.supermart.com/505-spray-f...s-p-17010.aspx
On the hobbs fusible, watch for sales at connecting threads. they sell it in crib size and also queen size. I get more bang for my buck by getting the queen and then cutting it up (use it ALOT on my QAYG stuff), here is a link (not on sale at the moment tho)
http://www.connectingthreads.com/too...usCtnBtng.html
Another good source on the Hobbs for me is Hobby Lobby, use the 40% coupons on the queen size and thats a great deal.
Post pics if you can of your 40 quilts (cant imagine doing that many), would love to see them, what a great thing you are doing.