I came across a 1923 Coleman Model 1 stove/oven on Craigslist the other day. I had never seen one of these stoves before. According to what I read online, they are the earliest model camp stove produced by Coleman. Having never seen one before and based on their age, I assume they are rare-ish. What's a decent price to pay for a complete 'average' 'original' Model 1?
The stove & oven were complete and in relatively good shape for it's age. The guy wanted $150.00 for it.

Not sure what it was worth, but it got me to wonder, how does a person find a fair price for an item like this? Are these Model 1's that rare that it would command such a price?
Thanks
Ted