In many markets, there hasn't been a single deep discount sale of a multifamily property.

I have not.I’m so deep in this one I’m probably not starting over. 

I won't go to deep into short sales, but there are a ton of additional costs that are associated with a deal like this.

So if one can buy dirt at a reasonable price get it approved and built and filled up as stated above they will force equity and have a very good investment that is worth a ton more when completed etc. the issue out this way is finding any dirt you can actually build a park on  most cities wont allow them then you have the other barriers to developement and absorption like I mentioned above these all factor into it.. out in the mid west and deep south one can buy a park for 7 to 10 cap all day long.. in OR WA CA your going to find it difficult to find a park above a 4 to 5 cap.

Both of them expect you to deep dive into your Business (generic and not focusing on real estate).

Over a few years capex exceeds cash flow - you are looking at a very deep money pit.You can tell also by the fact that these properties will often sit many months on the market while a 300k duplex sells in 2 days with 7 offers to local investors.

If you're up for it, testing a small version of your idea could give you a taste of its popularity before diving deep into the numbers.

I would love to deep dive on how to analyze a deal or how set criteria.

Unless there are holes, deep gouges or black stains from dog urine, I would sand and coat them with several coats of poly.

Most of them will know much more than you and have deep pockets.