http://www.skial.com/forums/skial-middleman.34/
Summary
You can buy and sell TF2 (Team Fortress 2) items with other people using a bot to hold the items, and Mtgox as the payment processor.
How it works
- The seller of the TF2 items will trade the bot using Steam trade and set a price either in Bitcoin or USD.
- The seller gives the buyer the tradeID.
- The buyer then deposits money into the bot with a Mtgox code.
- The buyer purchases the items with the tradeID.
- The seller can then withdraw the money from the bot through a Mtgox code. Or use the balance to buy other people's items.
Is it safe?
I have already tested multiple trades with several other people already, but no one can guarantee any system is completely safe. Our TF2 group has existed for about 2 years. Identities are managed by Steam, so we do not record your passwords. All transactions are logged.
It is always possible for Valve to clawback any items, especially if the items were gained by a credit-card chargeback. This is a fundamental problem for Steam, not an inherent problem in our system.
Can I sell anything else besides TF2 items?
Currently no. It is against the terms of agreement to sell Spiral Knights items, and there is a Valve support page that says you are not allowed to sell Steam gifts for money. We also do not have Portal 2.
Instructions are our forum.
http://www.skial.com/forums/skial-middleman.34/