I'm working with a seller to market her equestrian property in a VERY high-end bedroom community near Boston.

It's 10 acres with a very nice colonial, plus a guest house rented at $1,500/month, huge barn with 25 stalls that rent at $900/month each - though there's no guarantee that clients will remain.  There's an inground pool, paddocks, tack rooms, etc. 

Being in Massachusetts instead of say, Texas, horse properties are very few and far between - especially with 10 acres this close to Boston.

As you might expect, there are no good comps.

3 other big name brokerages have listed the property and have failed to sell it - each with about 200 days on market.  The seller has lowered her price by about 15%, which makes sense given the previous failed attempts at selling - but I'd really like to come up with something substantive to back that price up.

The big issue is that in this town, there are no equestrian sales for many years.

I attempted to create a metric by comparing sales of a few different styles of homes (3/2 capes, 2,000 sf +/-) in other towns that have some equestrian sales and the subject town and coming up with a percentage, and then applying that percentage to equestrian properties in the other towns.  It didn't seem meaningful.

My last resort is a professional appraisal, which I expect will cost $1,000 or more.  I could ask the seller to pay for it and reimburse her at closing.

Any ideas on how to give this seller a recommended price that we can both have confidence in?