Reconfirming with minor adjustment; it'll be three months old in three days.

http://www.tf2outpost.com/trade/12502334 BO 18, new trade/banned user

http://www.tf2outpost.com/trade/12366412 BO 20, Offers include; 15 keys + 2 summer keys; 50–60 USD

* http://www.tf2outpost.com/trade/12279579 Previous owner had a buyout of 18. Was up for only two days before being sold.

http://www.tf2outpost.com/trade/9576498 No BO, offers include; 22 keys (probable outlier, offerer bought one fast), 18 keys, P fetti HWH (15), Bubbling mirror (15). This trade is reallllyyyyy old and the SnS is duped.

http://www.tf2outpost.com/trade/10552954 BO 20, offers include 16, 18, 18 + 2 ref, 19, steaming pencil (14), peace buck (ew), S PDA + s Shotgun + Lime ebenezer + 5 keys (16, lot less after overpay), Buyout (didn't go through, though it is a recent-ish offer). This trade is reallllyyyyy old

http://www.tf2outpost.com/trade/12619910 BO 17, new trade

http://www.tf2outpost.com/trade/12594642 BO 20, new trade

http://www.tf2outpost.com/trade/12510055 BO 20, I bought it for 16. Trade was only up for three days so safe to say the owner was quickselling.

The rest of the trades on outpost are irrelevant.

It's clear that 17–18 is the preferred range for buyers. Twenty is a common buyout but it just ain't happenin' by the looks of it. Sellers have to work a little to get offers above 18, though they do occur. Anything above 19 or below 17 is an outlier.