Sometimes I hate trading.

So I'm looking for a backpack expander, and browsing TF2TP I stumble on this post: http://tf2tp.com/trade.php?trade=9347904
Since usually backpack expanders are sold for 2.5 keys or more, this one seems a deal. I add the guy on Steam and after some hours, he finally shows up. Screenshot of the conversation between me and the guy: http://puu.sh/2zyRN
I can understand changing your mind about a price, but stating that you wrote something when everyone can see that you wrote something else is ridiculous. Also, after removing him from my friends I tought everything was over, but no!, the guy even did this: http://puu.sh/2zyUP
I'm baffled.