Not sure what the value over a year ago has to do with short selling a commercial building, but it sounds like your first step should be to find a competent local broker to advise you.
Short sales are a complex process, and there are lots of ways to "fall off the tracks". For a start, I am sure you will find the value a year ago is irrelevant to the situation.
I am in California, but attending a conference on short sales and bank-owned properties with some of the best Realtors in North America. I can probably refer you to a competent advisor in your area.
You can contact me at Terry@SurfMLS.com
On commercial building , we can do the comps. We offen do commercial broker house opinions(BPO) for banks. We also have a full time staff for your short sale process. If you can email us the square footage, type use of the building (office,retail, warehouse).
We would be happy to forward you some comps. Email us at: 702commerical (at) gmail(dot)com
Team Aguilar 702-328-933 five
When the subject unit was bought as a foreclosure, it appears it was in the middle of price range compared to what others sold for at that time. If you are going to short sale, however, what is important is today's value. There may be a better way than short-selling the property to attain your goal. Let's talk about your options, you can call me at 702-808-9816