Haven't read the whole thread, so I don't know if this has been mentioned or not. Last year, I volunteered at the Boone, NC warehouse/distribution center. The told us that they really prefer people to not use the plastic boxes or really big paper shoeboxes. The plastic ones do not stack well (experienced this first hand as we could not stack the pallets very high w/ these), and the big boxes (like boot boxes, etc) cost more than the $7 to ship (many people don't send shipping money at all, so SP is having to cover shipping for those plus the extra for the big boxes). I know I've used the plastic one sin the past because I wnated the kids to get lots of stuff. However, I will just do more of the regular size paper boxes from now on.
Anyway, just wanted to post what we were told. Thanks to all who support this great ministry!