Why buy stickers? You can add a Y leg for $299 which would be the cost of 6 stickers, then you wouldn't have to worry about buying them. Even before the 2 NYC or BOS promo, I've been buying one way Y fares for every time I have had to go to NYC. I haven't had to pay for an upgrade in a while (I just burnt a bunch of upgrades when I flew to PAP over the holidays).