Did a quick search and came up with this link.
Alpine RUE-4202 Remote Control for 2005-2008 Head Units New

Paypal is easy to set up. Just go to their site and read up on it. Once oyu find the item you want on ebay you can use your pay pal account to pay. Pretty simple. If you are not comfortable with this then it seems like $20 is the going price for the remote.