I buy any kind of glitched TF2 items. This includes:
-Painted unpaintables ---> Add 5-20 keys for the Paint, in rare cases even more
-Crafted uncraftables ---> Add 5-20 keys for the Craft, in rare cases even more
-Gift wrapped non-wrappables ---> I'll pay 10-15 keys at least, more for rarer ones
-Glitched spec/pro killstreak items ---> Price highly depends on the item
-Glitched items with Killstreaker or Sheen missing ---> Price highly depends on the item
-Glitched War Paints ---> Price highly depends on the Wear
-Post life spelled weapons and cosmetics ---> Price highly depends on the item and spell
-Strange Unique weapons ---> I'll pay 2-3 digit amount of keys each
-Normal weapons ---> I'll pay low 3 digit amount of keys each
-Items with missing series ---> Add me to talk because i have no price in mind
-Painted items with red attribute missing ---> Add me to talk because i have no price in mind
-Stocks with glitched long Name/Description (40+ letters Name, 80+ letters Description) ---> 5+ keys each
-Items with Loaner Tag (only rare ones & Stranges) ---> Price highly depends on the item
And many more!

I also buy any kind of rare TF2 items. I am more picky for this though. This includes:
-All kind of single digit craft number items (#1-9) ---> Price highly depends on the craft number
-Double spelled Items/Unusuals ---> Price highly depends on the item and spell
-Any item with less than 100 known to exist ---> Price highly depends on the item
-Legacy Painted items ---> Add 1 key for the Paint, more for rarer ones
-Collector's cosmetics/hats ---> I'll pay 100+ keys each
-Restored items by Steam Support (Origin: Support Granted) ---> Price highly depends on the item
-Items with rare Levels ---> Price highly depends on the item
-Rare Vintage items ---> Price highly depends on the item
-Decorated weapons with rare skin patterns ---> Add me to talk
-Decorated weapons with rare stickers ---> Add me to talk
-Decorated weapons with rare color gems ---> Add me to talk
-Very old and special items (2009-2012) ---> Add me to talk
And many more!

Feel free to add me if you think something that you own is missing in my collection, i don't bite!
Even if i already own your item, there is a chance that i will buy yours as well.
NOTE: Don't expect me to pay moon prices though, i don't like to pay too much for an item.