Steam TF2 items value?

[griffy]

I've not played TF2 for ages, but recently keep getting pestered from a few people, asking to trade for a few items I have in my inventory.

Now it seems you can trade other players for in game hats etc, but how much are they worth for a trade?

For example, I have 'Bills Hat' which is tradeable but not sellable for cash it seems.... Although I noticed some people selling, or trying to sell a version of 'Bills Hat' for upto £60

What is Bills hat worth for a trade? How can I tell I'm not being ripped off?

Thanks in advance

 

[Hyburnate]

http://backpack.tf/

Edit:
http://backpack.tf/pricelist
Search it here.

http://forums.steampowered.com/forums/showthread.php?t=1904897

 

[KIA]

10-12 USD for a regular Bill's Hat.

 

[Hyburnate]

10-12 USD for a regular Bill's Hat.

Yup, and by checking your inventory that's the one you've got I think, to be honest, I'd keep it.