He could be running a scam but more likely he does just want the account to get some discounted ripples. But if you present a trade to someone and send them the money first and they agree to it and they receive the money and you deliver the goods, then no one was "scammed". That is a called a business transaction between consenting adults.
It would only be a scam if he bought an older account to do something scammy with on the site. The ripples thing is the most likely answer so not a scam.
The same person has offered to pay me to make a post including his receiving address. It does really seem he is only after the Ripples.