Would we not all supplement our good tenants rent by $200/month.If a landlord is operating a business in which costs rise annually why would they consider lowering their tenants rent when the market does not warrant it.

Plus hold money for property taxes plus the dreaded supplemental tax bill that will inevitably show up.

As for market rents, unlike many landlords I do not believe a well run business supplements tenants rent.

Eventually, I would like to supplement enough income to scale back to a 40-50hr work week at my job and break away from the turnkey side of it to further maximize returns. 

The main reason we'd like to get into RE is to help supplement our income since my wife stays home with our 3 young children.

Costar has good data, but you'll want to supplement with local research (apartments.com, craigslist, zillow, etc).

Supplementing your tenants rent is charity not business.

You will need to supplement your tennat $2500 rent out of pocket to cover the expenses on this property. 

After a few years, you can refinance to pull out cash or get a supplemental loan (if available).

I've also been looking at Slice.is (yes not a .com but a .is) for supplemental coverage.