That's not a bad idea, resolution is nearly irrelevant in what I want.

The best is to prepare for the worst, talk to a lender now pre=quality for a refinance ,make sure of your numbers when buying the asset 

With proper networking, education, and hands-on involvement, you'll be equipped to make your own decisions.

I've learned here that developing better systems, delegation of work/ responsibilities and building a team is the only way to maintain or increase project flow with the goal of achieving a better quality of life.  

Direct vented equipment can be a solution to both of those issues.

I'm not saying it's good or bad so there are some practical things to consider.

The problem is that the existing home was not maintained and has major issues (foundation, sagging floors, mold, possibly a new roof and new electrical) so I'm trying to get a ballpark for what it would cost to bring the existing house up to rental quality vs what it would cost to just bulldoze it and build new, or if its even worth touching at all considering the value of the property. 

In more astute owner/property manager interactions, the contractor will be TOLD to decrease their price ASAP or the contractor would be terminated for any future consideration.I would most definitely contact the contractor to get the low down as to why it is more, since the property manager won't do it.It sounds like since you are doing a la carte service as opposed to full service, you are getting some bad answers from the property manager. 

We have zero bad debt and 800 on credit scores, but maybe that doesn't matter for these kind of purchases?

A good property manager can make your life easy, a bad one will lose you money on your property.4.