Cart not working on firefox – Help needed ASAP

Hey there, please see attached. Just pushed live today, and everything is working perfectly in Chrome.

Client keeps sending me emails that cart is broken, cart is broken, did a test with her live while she was on the phone and she mentions she's on Firefox. Shopping cart is not working correctly on Firefox, we need this fixed asap.

When you go through checkout process in chrome, zero issues, everything goes as it should. In firefox, adding this coursepress class that's on sale to cart:

And then adding the blue color of this shop item:

And then going to shopping cart:

In Firefox, if you do the above steps, the formatting makes it look like the price of the Otsu Planner is on sale, attaching screenshot.

To add another layer on, see attached paypal error client is receiving when she sees this error on her end and tries to check out. On my end, when I was in firefox and saw the formatting error, I was still able to complete a paypal transaction.

This site was supposed to push live a week ago, client has a major email going out about a sale this evening and this needs to be working immediately.

I'm emailing you guys in a moment to provide login/ftp credentials as I'm heading offline for a meeting for the evening, but I'll be back online tonight to wrap up any loose ends.

Please reference this string for bug fixes and edits you guys helped me with over the past two weeks:

Hoang did edits right in the plugin files, please DO NOT reinstall marketpress/coursepress software to try and fix issue as we'll lose all the stuff we've been working up.

Please help me wpmudev kenobi, you're my only hope.

Thanks you guys for all that you do.