Just gonna copy and paste this since he's not resuggesting :^)

All credits to K1NG

Sale 1 - Was used to price the Warm-Up, so can't be used here.

http://backpack.tf/suggestion/58ea3a600e2cad29de68213d

Sale 2 - Sold for a DP Goggles (outdated at 16, 3-week-old seller for that) + 3 keys + ~2 in sweets

http://backpack.tf/profiles/76561198168625615#!/compare/1490400000/1490486400

http://www.tf2outpost.com/trade/28845894 ----- B/O was 19, but sold quickly.

Sale 3 - Only 4 keys match - Untraceable

http://backpack.tf/profiles/76561198087505590#!/compare/1488585600/1488672000

http://www.tf2outpost.com/trade/28802878 ----- Was looking for a Max's Head (19)

Sale 4 - Quicksold for 16 keys

http://backpack.tf/profiles/76561198123737401#!/compare/1490227200/1490313600

http://backpack.tf/profiles/76561198103058947#!/compare/1490140800/1490313600

http://www.tf2outpost.com/trade/28845405 ----- B/O was 16, sold in a day.

Sale 5 - Untraceable and will go outdated in 5 days

http://backpack.tf/profiles/76561198011321852#!/compare/1488067200/1488153600

http://backpack.tf/profiles/76561198138818087#!/compare/1488153600/1488240000

Sale 6 - Sold with 1 key for something that resold for a Blizzardy Grimm Hatte, which then resold for 20 keys

http://backpack.tf/profiles/76561198017112652#!/compare/1489104000/1489276800 ----- Keys match with Airdog seller and Jarool

http://backpack.tf/profiles/76561198299913218#!/compare/1489104000/1489190400 ----- KaW Trib doesn't match

http://backpack.tf/profiles/76561198021055079#!/compare/1489190400/1489276800 ----- Grimm Hatte matches with Airdog seller and Jarool

Can't say what was involved exactly, but this sale will end up at 19 for the Airdog.

Sale 7 - Quicksold for 14 keys indeed.

http://backpack.tf/profiles/76561198149435216#!/compare/1489881600/1491004800

Sale 8 - It's fine to value it at 20, although it will go outdated soon.

http://backpack.tf/profiles/76561198125852286#!/compare/1487980800/1488067200

http://backpack.tf/profiles/76561198149714212#!/compare/1487721600/1487980800

Other sales.

Sale 9 - Likely SCM

http://backpack.tf/profiles/76561198136755098#!/compare/1492905600/1494979200

http://backpack.tf/profiles/76561198113677851#!/compare/1490745600/1491177600

Sale 10 - Sold for a Flies Kabuto (outdated at 19, sellers for ~15) + minor sweets

http://backpack.tf/profiles/76561198011321852#!/compare/1490227200/1490313600

http://backpack.tf/profiles/76561198007870834#!/compare/1490227200/1490313600

Sale 11 - Sold with 2 keys and minor sweets for a TF Logo Airdog (22)

http://backpack.tf/profiles/76561198007870834#!/compare/1490227200/1490313600

http://backpack.tf/profiles/76561198123737401#!/compare/1490227200/1490313600

So, in summary, there are sales for: 14 (qs), ~15, 16 (qs), 19, 20, 20, 21(?). Taking 19-20 here and someone could use this to update the Goggles.