the degroot needs a mini (a small suggestion) due to the fact its duped. And you can't have a range with one sale.

Theres some more sales:

Sale 1: (Your sale)

Sold for stormy pillar (~31 via mini) + NnB degroot (~12?)

http://www.tf2outpost.com/trade/26238691

http://backpack.tf/profiles/76561198134322282?time=1437507568 before

http://backpack.tf/profiles/76561198134322282?time=1437548400 after

The degroot has contradicting suggestions (at 11 flat and at 11-14), personally support the 11-14 one more. Taking average of both suggestions, which would be rounded to ~12.

The fact that the degroot is duped does not really matter. Dupeds below ~25 keys can be used without a necessary mini (given that theyre updated).

Mini tower: http://backpack.tf/vote/id/55ae05eddea9e91d6e8b45f0 open suggestion at 31

0.9*(31+12) = ~ 39

-> 39 keys

Sale 2:

Seems to have sold for duped DbD cold killer (32 via mini)

http://backpack.tf/item/1976962189 for http://backpack.tf/item/1664754503

the cosa doesnt seem to be involved. Since this is your trade you can probably confirm/counter with what actually happened

Mini cold killer:

Sold for aussie scatter? (~32)

http://backpack.tf/profiles/76561198134322282?time=1434610800 before

http://backpack.tf/profiles/76561198134322282?time=1434727335 after

-> 32 keys

Sale 3:

Seems to have sold for presidents exe (~38 via mini)

(histories are crammed together pretty heavily here, due to it selling in quick succession a couple of times).

http://backpack.tf/item/2748514207 for http://backpack.tf/item/1664754503

http://backpack.tf/profiles/76561198140026187?time=1434610800 before

http://backpack.tf/profiles/76561198140026187?time=1434745203 after

Again, I cant link the cosa to anything in this trade.

0.9*38 = ~34

-> 34 keys

Sale 4:

Cant find out what this sold for, none of the items have matching item histories and I cannot find it in the buyers bp.

http://www.tf2outpost.com/trade/26232515 BO 32 supports the drop

http://www.tf2outpost.com/trade/26224136 has been for sale at 40 before

http://backpack.tf/profiles/76561198135943552?time=1434610800 before

http://backpack.tf/profiles/76561198135943552?time=1434740535 after

Sale 5:

Probably sold for CSGO stuff

http://www.tf2outpost.com/trade/26140530

http://backpack.tf/profiles/76561198094417563?time=1434265200 before

http://backpack.tf/profiles/76561198094417563?time=1434393621 after

Cant really use this.

This one is the only clean ones with recent sales.

Other histories:

http://backpack.tf/item/1675966989 hasnt been sold in over a year

http://backpack.tf/item/1679430988 duped

If you can confirm the DbD cold killer sale (i.e if it was 1:1ed and if you did buy it for an aussie scatter) you could suggest for 32-39. If I got it wrong, you can probably use 34-39.