Actually, most internet retailers don’t do their own shopping cart or other financial mechanics of retailing. That’s a module or outsourced service they wire into their web site.
Same deal for the shipping charges.
That’s what makes ‘net retailing so fast and easy to set up. You can outsource the complications that used to take so much time to other providers that specialize in these matters and really know their subject area.
Yes I had an online site for 3 years. It still going to be a pain in the azz. Plus it will up the cost of the online products. Its not going to be good. But of course neither is the cyber security bill they just passed.