Sales tax screwed up

Sales tax is subtracted from the item price (see screen shot "screwed up tax 1) at this page:
http://wp.barryclemson.net/mp-store/mp-shopping-cart/

Final price reflects the subtraction of sales tax (see screen shot "screwed up tax 2) at this page:
https://www.paypal.com/us/cgi-bin/webscr?cmd=_flow&SESSION=5o0JzFRQyPUZMCfyxwfWoYEFbOdnpCPBcq-CCJKNlw8A7lBziAS-jwsPtQC&dispatch=50a222a57771920b6a3d7b606239e4d529b525e0b7e69bf0224adecfb0124e9b61f737ba21b081988562bf19d61623c669b34e5cd175ba4a