Your answers to these questions will determine if you think a refinance is a better option than selling.Note the ~$45K invested well can produce a return that can cover negative cash flow.We purchase value add properties. 

Manufacturers generally want a large number of units to produce because repetition and quantity lend themselves well to the manufacturing environment.

Funnel as much of that cash flow into income producing property managed by someone else inside your org or by outside sponsors.They key is to grow funnels of income in business.

Ofren the case when property is income producing.

So my question is, is it wise to put more money towards principal on an investment property given that my goal is to produce cash flow?

Then they try to land the end tenant or end user to buy the land and only close on it when they feel confident about it.To close on land and hope It works out you have to get it for a very low price otherwise it can sit for years and you pay property taxes on it and not producing any income.

My goal is to produce leads to flip single family homes.

I am hoping to get a comprehensive table with all zip codes, because I want to combine with some other data sources to produce some insights and maps.

I would have to guess it would take 10+ hours if you include the help you are asking on this forum + reading all the instructions.And it will still produce the wrong result. 10 hours or 40 hours later.I have over 20 years of experience, and I would not try to do it by hand.

what is it exactly about the listings that isn't producing results?