If it's 15 years old, not so much.The rental comps will tell you what gross income to expect as long as you compare it to nearby similar properties in the same condition.Having said that, there's no absolute guarantee.

And with the new tax laws benefiting real estate investors, the comparable return is even higher.

Current rent seems to be a fair market price given the condition of the propertythe county appraisal value is significantly low compared to asking price (asking price is about 4 times).

For my lender the draws are set up initially, then you call when you are ready for a draw, we send an inspector out that compares your SOW and the work done.

While appraisers do need to include actives/pendings in their report, a sold comparable will carry primary weight.

Keeping the rentals in their current condition (compared to other rentals in similar condition) we can raise rent to a gross monthly rent of $4350.

Watch where rent prices are compared to home sale prices.

The ones I've seen are giving the lowest returns compared to single family.How many units are you looking to buy?

Compare that to the return that you would see if you invested. 

@Clark Kahawaii thanks for posting this.  4-plexes in Dallas are a lot scarcer than other markets and I've got some thoughts on just some things to consider:Comparables - with Multi-Family units in DFW finding comparable properties (comps) can be challenging.