Frankly, we have the extra money to make up for small negative cash flow that say a 15yr mortgage would give.

Expensive yes, but the foundation companies say a big culprit is the lack of steel in the foundation (older homes), often followed by beam size and other environmental factors.

If let's say a home is worth 100K, and you can buy it for 80K, and make repairs valued at 10K, you own the home for 90K.

I will caution you that sometimes you'll find an estimate WAY off at one of the sites (I had 4 sites say a house was around $120k and the 5th side $420k) - just remove that one from your averages.For the sake of examples, let's use the numbers you have ($65k & $80k).  

Now single tenants charges above market per sq ft lease rates and if it goes dark likely your second generational tenant will not pay those rates.So if you buy at a 6 cap to 6.5% based on say a 35 sq ft rate for a good area and they go dark and it drops down to 25 sq ft for the second tenant going in you now have a crappy cap rate lower than your debt interest rate.Now if you have a corporate Steak N Shake there is more security as it doesn't matter if the store is losing money all the corporate stores prop it up guaranteed by the lease versus a small franchisee that takes a bath after one to two years of opening.I have decades of restaurant experience and after reviewing the FDD ( franchise disclosure documents) a few things became clear.

What is your opinion are these large swaths of boarded up homes we see in the mid west upper rust belt ruining these cities or are they an investors dream opportunity to get into the RE game for ridiculously low price points Vis a Vi the historical norm..Say a 1k house in Detroit that sold 10 years ago for over 100k..

Then I make my offer and DON'T SAY A WORD until they respond!!

Managing 50 units can occupy a lot of time but say a 4 or 8 unit can be much more manageable.

For example, lets say a home is 100kIn order to buy it for 70% arv, and lets say it needs 20k in improvements, I would have to try and but it for 50k ?

For lets say a 2000sf House?