We aren't offering discounts, but instead are giving them the option of paying the deposit then splitting the balance into 2 or 3 monthly payments with the first one due at completion. We do this after offering leasing by others.
We bury the interest in the estimate. We may be higher, but the customer likes the idea of making payments rather than all of it at install.
If a payment is missed then interest is tacked on again. You have to be able to go with your gut on who you offer it to though. So far we have been pretty lucky and the payments keep coming in.
The companies that are low balling the jobs can't afford, or won't, offer payment plans.