I'm pretty sure I got offered 5 PURE numerous times on my trade.

So it was phantom + 29 keys + 4.5 keys in sweets. At the time of the sale, buds were ~16.5. That would put the sale at 5.3. 4.8

Duped beams merry at 5 seems really low.

http://forums.backpack.tf/index.php?/topic/6033-new-unusual-price-suggestion-guide-the-cheat-sheet/#entry167485 - typically at hats of this value, the reduction is ~10% for being duped. You have taken off more than 20%. And there are couple of issues with that sale. For one, you have applied overpay twice. First on the attendant, then on the merry. The idea of overpay is to give an estimate of a hat's worth in pure. You are calling the merry 5.5 in pure after overpay. So it should be taken as 5.5 in sale value without doing overpay a second time.

http://www.tf2outpost.com/trade/20285898 - this duped beams merry sold for blizz ke + 10 keys ~5.5 as well. Beams merry as ~5.5 in pure might be fair after all.

I think a range of 5.3-5.5 would be fine. Low end as it stands feels low.