In speaking with a technical support person yesterday, he told me that they do not offer discounts.
I tried again today and called customer support. They said that if I send in the unit and they find that they are unable to fix it, they will offer a better price for replacement. He was unable to tell me how much of a break they would give me, but at least it is a first step. As the unit works most of the time, I will pull it out over the winter and send it in to find out what they might offer.