I've just put one of the portfolios in the mail from Australia to the US for about $A55. That is a bit expensive but it's well worth it to participate and see others' prints. If it's a once a year expense, I don't think it's a big deal.
I hadn't seen this thread until now so my print's mounted and matted, I really liked seeing others the same way. From now on I'll use 2 ply. This portfolio has a number of platinum prints and other contact prints, hopefully it might include a carbon transfer print soon (Vaughn?). I tend to think these alternative, especially irreplacable, prints should have as much protection as the creator wants and I wouldn't want anyone to be dissuaded from putting them in.