How much should a used garage door and opening system sell for?

[grgdoorfix]

We are having to convert the 2 car garage door makes popping noise when opening to a bedroom. Trying to sell the tracks, door, ceiling mount engine (craftsman), wall opener, and 2 car openers on craigslist. All is less than 5 years old and in great condition. Door is one big door, standard 20x20 garage size. Our contractor doing the work said around $500 as the doors are over a thousand new, plus the cost of the engine. What do you think? How much should I ask? I want to be fair, but we need to offset some costs for the baby on its way in a couple months...