In terms of payment method,I can do as much as I can to cooperate the seller.
I don't know how long will it take to increase my limit in coinbase or byitstamp,I am sure I have already verified completely.
Be sure to use a trusted escrow when trading with anyone. Trust me on this advice. You will be thankful you did.
Never send money or coins upfront . You would never send or loan money to strangers without any assurances of repayment, would you? Sending money first to anyone here is similar to loaning them money. In return for coins or money sent first, you are promised the same value with a certain margin. That's essentially a loan. Go to the loans section and see how strict lenders are with their collateral requirement.
What I'm saying is when you trade with anyone on the exchange section, treat the trade or transaction as a form of lending. You have the money and you want coins. Now someone wants your money and offers to give you the coins you need. Would you send the money first? No, right? So the solution is to use a trusted escrow who will hold the "collateral" (the coins) before you send the money. The safe way forward.