let's just get to the point.

Sale 1:

Sold for a KaW Magnificent Mongolian and 9 keys

http://imgur.com/N4ojn1t , http://imgur.com/77vQQu8 , http://imgur.com/6ryUlsP

Mini for KaW Mongolian:

Sold for 8 keys

http://imgur.com/SToR919 , http://imgur.com/sTQqU9O

9+8*0.9 = 16.2, Rounding down to 16.

Sale 2:

http://backpack.tf/profiles/76561198139121370?time=1423382400&compare=1423728000

Appears to have been sold alongside some Earbuds for a duped GE Capotain. Sale is really old so not using.

Sale 3:

http://backpack.tf/profiles/76561198079848769?time=1448265600&compare=1448352000

Appears to have been sold alongside 2 keys for a gifted Flaming Lantern Topi. Topi is really outdated and I can't find a mini for a gifted one, so I won't use this sale.

Sale 4:

https://scrap.tf/auctions/4EK2RG

Automated auction on scrap.tf. Sold for a NNB Private Eye. Don't really know the circumstances surrounding these kinds of sales so I won't use it. Private Eye is outdated anyways.

Can't find any other sales.

Bottom line: 16 keys. Feel free to tell me if I did anything wrong in the comments!