im surprised i haven't suggested anything for this until now (used mini to make TW cowl suggestion, go check it out!)

HG BD + CH regg for a TW cowl

proof:

http://backpack.tf/item/623179518

http://backpack.tf/item/3321820692

for

http://backpack.tf/item/1748936419

cowl mini:

sold for this stuff

http://www.tf2outpost.com/trade/25748250

26 + 23 + 15 + 15 (mini, using his b/o) + 12 (mini, using his b/o) + 13 (mini, using his b/o) = 104 keys, 104 x .9 = 94 (rounded)

reggae + bone dome x .9 = 94 keys

(57 keys) + (X) x .9 = 94 keys

51 (rounded) + .9(x) = 94 keys

.9(x) = 43 keys

43 x .9 = 38.7, rounding up to 39 keys

other one on market includes is duped item, so i won't use it since i found this one

--- http://backpack.tf/profiles/76561198088708386?time=1426336360 (the GE festiveizer is duped)

supportive proof: http://www.tf2outpost.com/trade/25555102 (asking for 40 keys)