Make your pitch

Offer a free trial and a free installation. Charge for maintenance and use of your solution later on. If you sign a contract, make sure it is not exclusive. After all, the goal is to sell the solution as a product to other companies. Who knows, you may even expand into other industries later on.

Make sure to form a separate entity to handle the invoices, bills, and contracts rather than signing anything as an employee of your current company.