My previous suggestion got shot down, so here I am again with an even more suitable range. :) ((Same proof + one more sale))

1 in existence, 1 on the market

http://www.tf2outpost.com/trade/11685370 (old owner)

Offered hat + .5 buds in items, fighting-fedora w/ orbiting planets found in bp (23-29) + at least 12 keys

http://www.tf2outpost.com/trade/11708958 (current owner)

Offer of memory leak private eye (not yet appraised)

http://www.tf2outpost.com/trade/11708958 - appears to have sold for a lvl1 max head: http://www.tf2outpost.com/item/440/1730312552/162/6

Taking unusual overpay in mind I've set up a suitable range for now, might need a bump as time goes by.