Well, the first thing to do is have a chat with your banker, and your supply house. If nothing else, a Dun & Bradstreet report will give you an idea as to how eager they are to pay their bills.
You're going to get stuck with any warranty issues regardless, so you need to allow for that in your pricing.
Whoever buys the lights, it will be necessary for there to be protected storage for them.
Why should you save them money? That is, if your business model depends upon parts mark-up to cover the hourly rate, then you're in trouble if the customer buys direct.