I've got it all set but its not on my store yet. You could private message me if you dont want to wait. I'm packaging a whole bundle together. The bundle includes the construct 2 plugins needed, the mysql database file, the facebook purchase html files, and the php/htaccess files.
Altogether you can:
1:Process up to two in app purchases via facebook securely. The php file verifies the payment belongs to a set user on the server side so no one can grab someone elses payment. The payment is verified against all payments previously saved into the mysql database, so if someone tries to repeat their payment via ajax........ they will find out its impossible.
2:Utilize a player database that comes preprogrammed with score, level, and up to two in app items.
3:Interact with the database in a way that expires which limits the potential for users manually adjusting the score and level. Paid items cannot be added without an unused Facebook payment, so no worries there.
4: Facebook plugin and Facebook payment plugin for C2 streamline the process of implementing payments or other Facebook features. <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile">
5: Mysql plugin streamlines the process of interacting with the database.
6: It's not a 1 app database. All your apps can share the same database/plugin without fear of corrupting any data.
All that being said, the php interface uses human readable urls, so you could easily enough, just use the Ajax plugin if you decide to add new functionality to the database/php code. It's also a pretty user friendly php interface which you can add functionality to without a lot of effort.
So if your interested, let me know. I plan on having it on my store http://shop.lockegames.com soon enough. If you can't wait just send me a PM or an email to lance@lockegames.com. You could look my up on Facebook at facebook.com/hikenh as well.