I'd love to be able to duplicate the functions of the DIS/Modic, but $460USD for an interface is too much money.

Buying the cracked software is a federal crime (we all wish we could live in Amsterdam). That leaves the interface which I assume is a RS-432 box. This leaves another problem - newer laptops don't have a RS-432 port.

Get the USB interface into production. Stop selling the cracked software. Drop the interface price to your cost to your cost plus a reasonable markup, and maybe you'll have a sellable product.