if you have bitcointalk member and joined bitmixer campaign, im interesting to buy it 
my budget 0.05
I hope you made your research first before you posted a "Wanted to Buy" thread. First Bitmixer signature campaign only accepts Senior Members so what you are technically buying is a Senior Account that fetch at around 0.08 BTC or higher. my budget 0.05
Second, I don't think you can change the Bitcoin address attached to the account because removing and changing the Bitcoin address will cause an error unless I'm wrong on that part and if seller is willing to sell the account together with the Bitcoin address and private keys.
