All credits to my bro, Polar.

http://www.tf2outpost.com/trade/24359276 - this is the 7.5 pure

http://backpack.tf/profiles/76561197960468927?time=1423209600 - here are the 110 keys in the 9.2 pure sale

http://www.tf2outpost.com/trade/24793013 - added ~4-5 for a shadows sam ~10

http://backpack.tf/profiles/76561198153140246?time=1422086400 - hearts nappers + dad robo tower (suggestion for that at 4.6) ~8

http://www.tf2outpost.com/trade/24843532 - true quicksell?

Purple Turtle, the person in your first trade, is SR marked. I wouldn't use that one.

Sales here at 6, 7.5, 8, 8, 9.2, 10. I would go with 7.5-9.2 as indicated in comments. Both those sales are pure, anyways.