What other kinds of loans or financing strategies are available that don't involve using too much of your own cash?

A link to FilePlace is at the bottom of every page, making it easy to find.If you have technical issues, email support@biggerpockets.com, and someone will help you.

If they replicate that kind of profit reliably, what would they need you for? 

My plan would be use the 401k kind of like a hard money loan where I'd acquire the property, rehab it, then refinance long term, pay off the 401k loan and get it rented.

Maybe selling is an idea worth considering if the house is a Mona Lisa and kind of beyond the general reality of typical tenant's maintenance obligation and ability, and they aren't paying for the additional quality.If you really want to keep the home, you may find a way to be very happy about it with the right team, whether it be property management, electricians, contractors, or tenants.

interest rates just don't support it right now. 

And thanks for those kind words. 

There are actually THREE kinds of subject to transactions1- subject to existing mortgage without lender approval2- subject to existing mortgage WITH lender approval3- subject to existing mortgage as part of a seller financed wrap around mortgage.with #1 and #3 it’s in everyone’s interest to utilize a third party servicer, who collects and then distributes payments.  

Insane.Personally that kind of rule alone would make me avoid the area completely.

This would further support the recommendation to negotiate a step-down mortgage structure, such as tiered payments or interest rates, to reconcile the seller's valuation expectations with the practical realities of the park’s financial performance and provide a feasible acquisition pathway.