The house is older and needs new roof, furnace, electrical, plumbing, flooring, windows and a basic landscape job.

So we outline all major systems (plumbing, electric, hvac), roofing, siding, windows, flooring, ect.

Assuming foundation/electrical/roofing is okay, could anyone give a ball-park estimate on the cost of repairs?

You are also going to need to have policies and procedures in place so the tenant doesn't think that it ok to call you at midnight because their A/C is not working.  

@Dane FosseeLet's say a person with no credit history apply for a Cap one card their score will shoot through the roof but do that show they pay their bills not all because there are no credit histories and that is the reason to look at over-all credit.

I think it would be easier to manage and maintain if it was all under one roof.

Some of the maintenance is more of a fixed cost while other maintenance is difficult to estimate (roof repair, plumbing issues, appliance replacement, etc.).  

The last house I purchased, I called my agent, he inspected the roof (it's Texas, it hails!)

I have come to the realization that to buy a house that cash flows in my area, it's going to need some work.  

Does anyone besides me HATE tan roofs???