I would venture to guess something in the range of $600 to $800 is reasonable for a product such as this one.

Keep in mind that the moving parts on equipment such as this wear out pretty quickly, even when it hasn't been used very much. You said that the unit has been used very little. Check the iris, the focus mechanism, cooling fan, etc. See if you can play with a new one to compare it to. Spare parts are, and will always be available for these, but it adds to the cost when you buy a used one. FEL lamps are really cheap though. They also last a long time, if the unit is operated and maintained properly.

I would venture to guess that this model is a knock off of the Strong Trouperette IV follow spot. At this point though, there is probably very little difference in quality between any of the differernt brands out there for this model, excluding companies such as American DJ.

I found new ones of this brand and others with similar features that use the same lamp advertised for $900 - $1300. Could not track down any used ones for sale anywhere. Most of the used follow spots out there are all of the much more sophisticated and expensive variety.

Good luck!