What a beautiful job @Kate Murphy! I am impressed with your general timeline looking at the purchase dates, etc. You have a good knack for what needs to be done.
I analyze the price of properties in many different ways and would disagree on the current pricing. In looking at your comps based on what has sold, I see that you are a bit smaller (about 200SF) than anything that has sold in the last year. I combine some formulas of what has sold, cost per square foot, unit types and current market conditions. On my back of a napkin analysis you might be overpriced based on the micro-climate of this specific neighborhood. All in all for metro Boston these seem like a steal but hard to prove at the micro level.
There are some other tell tale signs your agent will recognize on being over priced like drop in interest after initial listing, open house traffic compared to other available properties etc.
All in all I think there are two good choices: 1. Refi into traditional mortgage get 1 year leases and advertise next year. 2. Improve the price. I know how tight margins can be on these projects, so option 1 might be the best to let the neighborhood catch up and get some better comps. I wish you the best of luck!
EDIT: One thing I didn't mention on my initial post is that all of your comps have a lot of days on market. From my quick review its 70 days to Offer