I'll be moving this to the Pre-Sales forum directly after I post this, just so you know.
JFBConnect has multiple settings for and is compatible with showing your site within a Facebook Page Tab. We support Reveal Pages (to get users to Like your page before seeing the rest of your site) as well as a special template for Page Tabs and other features.
I'm not sure what you mean by " if attribute changes the price it does not work in facebook", so I can't really respond to that. However, if you purchase JFBConnect, and run into issues, we'll gladly help you figure out any problems. If we can't, you're always free to take advantage of our 30-day money back guarantee.
Thanks,
Alex