Dear Lillian:
Yes there is an in expensive cart called "Minicart" $75.00 for a unix or windows server or its bigger brother EZShopper $285.00 from the same programmers at
www.ahg.com compatible with a few credit card processors (ask which ones). I have a Florida business selling an excellent health book "Real Health Remedies! at
www.realhealthremedies.com that uses this cart. You can of course sell more than one item in the cart. I solved the 5 different tax rates covering 67 Florida counties problem by using the Minicart drop down tax window to have the purchaser choose their own tax rate from the list. For $35.00
www.ahg.com will customize the cart as in my case to stop any Florida address customer from completing a purchase without choosing a tax rate. For about the same rate they will change the cart calculation to total the tax rate selected to multiply against the total of the product price AND the shipping/ handling charge. You must charge against the total, most carts only tax the product charge. Ahg.com will produce an error page sending the Florida shopper back to the enter sales tax rate page if they fail to tax themselves. Check out my website to see how it operates and you might want to order my book.