I always say that paying by gift or helping with fees is appreciated but not required. I'm used to seeing this in other communities as well (all the time with BPAL perfumes - and there, some require it to be paid by thebuyer). If a seller asks me to, I'm happy to pay fees. If they don't ask, then I don't. If I know them - I'll send as gift (as I've done for some MLP people I've bought from). I'm used to being asked and asking. While it seems that most people in this thread are against it, it is fairly common to at least ask ....but I don't see a lot of people *requiring* it
in fact, for larger purchases, I will include a link to the paypal fee calculator so the buyer can see how much in fees i'll lose on the transaction (Which has been $5-15 for some more expensive ponies), and if they send as gift/friend (either free or a muuuuuuch smaller fee) or at least help cover part of it, it make a huge difference.