But in order to do this, I'd need to take on an additional $70K in debt to finance the basement rehab effort.

I don’t know of anyone personally who put the effort into getting the money back guarantee because it’s designed to be an almost impossible process. 

I don't think I could put in all the effort it takes with our portfolio to say, "One day - years down the line, this will all be worth it when I see a tangible return on my investment."  

It's easy to obtain, costs very little, and doesn't require extra, on-going effort to maintain.

This raises a critical question: Is there a genuine rental demand in these areas, despite the city's ongoing efforts to enhance infrastructure?

If you are going to select a Realtor, Banker, Wholesaler select them based on industry knowledge, tenure and success in their field.I offer this in an effort to avoid lost money and most importantly lost time...

While Solo 401(k)s are still subject to UBIT, the absence of UDFI can simplify tax considerations and reduce potential liabilities.Structuring for Tax and Liability Benefits:While some investors consider setting up an LLC to loan money to a syndication, this approach is often overly complicated and not typically worth the effort, especially from the syndicator's perspective.

Lack of persistence/effort/need does.

However, one have to put in the work and the effort necessary to succeed. that goes for everything in life. 

Recommend you start putting more effort into your business or you won't succeed:)BTWL most PHCs will require 3-5 rental comparables to support any rent increase request.