Only you can make the determination if its worthwhile for YOU to move forward on this, just know what you are getting into. Each person has a different take and what might not be worthwhile for another, might be great for me.
It looks like you have some good arguments on both sides of the table here.
You still have a chance to re run your marketing and generate some new test results based on the suggested test ad that can be found on the forum at not too high a price. Don’t rationalize that as a possible suggestion of why the demand is not there. Remember, its not like the movie , if you build it they will come. You can fix a park, you can not fix a market. Your first sentence states you think it is something to walk away from and sometimes you have to trust yourself.
If you move forward with it, let us know how it works out. I think you need more concession if you go with it as well.
If you are starting with 160k or even 80k, you should be able to get a better deal than this but its going to take some work to find that one.