Trying my hand at unusual suggestions, Ill try and keep it short.

Sold recently for a Ge Hiveminder and a PE Handymans Handle, and a few proffesional killstreaks with a double cross com. Bp after trade http://backpack.tf/profiles/76561198048506541?time=1405234800

Before trade- http://backpack.tf/profiles/76561198048506541?time=1405148400

Hiveminder only recent sale I can find with it listing what it sold for is here-http://www.tf2outpost.com/trade/20161973

Which is a Scorching Elfin(4.2) Vivid Western wear(1.4) 1 bud pure, and a Austalium Sniper(2.4). So for a mini suggestion, would suggest raising the price to somehwere around 8-9ish? Also previous owners were asking around that also. So for simplicity well call it 8.5 buds on the hiveminder.

The handle is currently valued by bp.tf at 1.9 buds, which still seems pretty accurate after looking on outpost. Rounding off to a flat 2 for pricing sakes.

The professional killstreaks will be hard to price, Most recent steam sales for the degreaser is $25-$30. http://steamcommunity.com/market/listings/440/Strange%20Professional%20Killstreak%20Degreaser Which translates roughly to 12-14 keys.

The flareguns recent sells would average to around $10 or about 4-5 keys. http://steamcommunity.com/market/listings/440/Strange%20Professional%20Killstreak%20Flare%20Gun

The powerjacks sales have been around $15 also http://steamcommunity.com/market/listings/440/Strange%20Professional%20Killstreak%20Powerjack so putting a 7 key or so range on this one. Which would add up to about 27 ish keys in total with the double crosscom which equals a rough 1.4 buds. This hat is rare and rarley traded. Cannot seem to find any previous sales with them listing what they sold at all or being able to fetch the bp valued from it. Its a rare hat, 1 of 1 on the market, has been for well over a year also. Feedback is appreciated and sorry for the wall of text.

EDIT: Re-suggested with flat price.