I'd also love this information.
It's hard to appraise camps because there are so few camp sales and they are often compared to other special purpose properties that aren't at all equivalent, such as old colleges or large churches. Since these other properties are generally in more populated areas, conversion to housing or office is a possibility, making them worth significantly more, and thus can often sell at a much higher price than a camp location in the middle of no where.
There's at least a handful of current listings on this site for which you might want to contact the owners to compare what they are selling. Warning, many are priced way higher than they can realistically sell their property for and will thus sit on the market for years, so take that into account as well. I've seen such properties sell for as low as 25% of original listing price.