500403 Membership site needs to become a subscription site.

My web site here: [login to view URL] currently allows visitors to purchase a year membership using Paypal for 9.95. It has a script that enables me to send renewal notices and people can again buy another year for 9.95. I would like to change the site to a subscription site, and if possible, add Google as a purchase method if it supports subscriptions. This would enable people to renew automatically for the lower price of 4.95. INTERMEDIATE skills required: FrontPage, ASPX, PayPal (and possibly Google payment) and HTML. My current programmer that won't be able to do this would have required about 2 hours for the work. Please see screenshots attached.