But when it comes to starting a portfolio of rental properties, it gets really expensive to do so.

Rood and siding is in good condition, and the first major expense I see in the next five years would be replacing all windows. with a 15 year mortgage, at 5% (I'd rather budget high than low) cash flow would be 6056/year.

If you're seeing net $200 after all expenses then absolutely go for it.

Forming/ placing even a short wall is of course more expensive than a slab.  

They are homes in great shape but not real expensive ...anyone know of a lender that I can use to get this refi at a decent rate?

I did calculate 5% for vacancy and 5% for expenditures for unknown expenses. 

About 1000sq ft)Monthly expenses including mortgage, taxes, insurance, hoa etc: $950Rents $1450/moSo it feels like a good deal but here's the kicker, it needs a new furnace/ac which is a combined unit that is outside.

What expenses do I need to include and what is a good average amount for each.

One thing not listed here is that the newer home may have a s high as 4% taxes, where the oder one may have 1%.Foundations issues and a new roof are expensive, though, i I agree, this one may not be the best wholesale deal to find. 

It makes quite an overwhelming statement and it's definitely not the most attractive part of the stairs.