(its in a midwest (basically forget appreciation), not sure if its relevant) Foundation is ok and structurally okPrice 60K seller carry 50K, I have to come up with 10K cash to put down, three units out of four occupied, rents 2K...

You have your entire future ahead of you - set a strong foundation and you will be successful! 

Overall condition of property (plumbing, roof, foundation, etc) since that is how you'll get spanked on a special assessment. 

But if you live in an area where you can make buying work, why not really set the foundation for your financial independence in the years ahead?

The average rents for comparable properties was $1,368The average sq ft was ~1100Most properties were 2/1's; most did not have a backyardAll properties had to mid-level rehab, some are very high-end and could be considered outliersAnalysis can be found at this spreadsheet. 

My interests lie in buy and hold rental investing and just now reading How to Invest in Real Estate by Josh Dorkin and Brandon Turner to build a foundation.

Financing will be easier if the home is on a permanent foundation and the newer it is, the better.

There's also some deferred maintenance relating to roof and foundation. 

Purchase price: $21,252 Cash invested: $45,000 I'm doing a complete remodel of a little two bedroom home, including some new foundation work.

Everyone has to start from somewhere and you will make mistakes but you have to have a solid foundation poured to build your success on.