"going on the low end of lease rates for comparable properties, would give an investor a cap rate of approx 10% at list price"
If it is not currently leased up with cash flow you can't go off of POTENTIAL cap rates. Remember this is the number one mistake time and time again. If you have a property that COULD rent out you only have a building based on square feet at that point. An investor will want to get it cheap as they will have to put the work in to rent it out and cash flow it.
Have you marketed the property to lawyers,doctors,dentists,accountants in the area and their trade organization chapters? You would need to check and make sure your zoning would allow for such uses. If the property is almost paid off you could offer a bug downpayment and you finance the rest at below market interest rate with a balloon note in 3 years.
Many are doing this as the financing has dried up on wall street without buyers putting down massive down payments. Even with say 30 percent down lenders do not want to loan out on properties that are not cash flowing already as they are to risky.
Then what you are left with is all cash buyers at a steep discount or doing some form of owner finance with some down from the buyer.
For solds your local mls will be mainly residential with limited commercial data. For that you need to go to
www.loopnet.com and
www.costar.comBuildings can be broken down into age of a class A,B,C,D building. Once you have the age you can then derive a cap if it is cash flowing already if not you look at similar buildings even a little further away that were vacant and sold on a square foot basis. Look up who bought it and market to them as they generally focus or specialize in acquiring one type of asset class.
You might find that a class C building of 20 to 30 years old might sell at a cap rate of 13 compared to a class A building (brand new with nicer amenities,location,and features is selling with the same cash flow for a 10 cap.
hope it helps