A good tenant is someone who works hard to have more choices in life.

Some, but not a lot of choices are rare do any of the prices make sense to me.   

Austin is a fantastic market, with its growing tech presence and vibrant culture, making it a great choice for your future career. 

Prices remain relatively low, but appreciation may be slower.Monroe: A mix of cash flow and appreciation potential, Monroe has become a popular choice for investors, especially in areas where new developments are popping up.Appreciation-Focused NeighborhoodsBallantyne: A well-established area with high demand, Ballantyne offers excellent long-term appreciation potential, though cash flow opportunities may be limited.South End: A booming urban hub with a vibrant retail and restaurant scene.

AND, your son will be at the mercy of the SELLER and dependent on the SELLER's good choices for the life of the loan.

Your best bet would be creating it yourself in excel.

If you don't fall within that category a knowledgeable local real estate agent can be an excellent resource.

As far as benefit to the seller goes, @Matthew Paul I think you are probably right on the money and regardless of whether they would have preferred to stay in this house rather than move, it is likely providing them some excellent cash flow; and I'd be hard-pressed to come up with a deal that serves both parties better than the current situation. 

Excellent explanation!

Since you won't be able to recognize it as a valid rental if you're charging under market rent and you also expect to be covering any house expenses that are outside of her budget, this seems the best choice.