Since they are generally speaking 'too big to ship', some semblance of your location will assist in pricing as well, and might even generate interest from a member if in your area.

(though sales should be kept to the sale page, outlined by Todd's sticky thread on the main page)

i.e. If you're selling in NYC metro, they'd probably fetch much more than if you're in Yellowknife.

If planning for insurance purposes, then I think you'd go with the higher of the estimates of course, for 'replacement' value.