We already paid them a pretty sizeable entry fee ($30k) to cover some of their equity and debt in another project..Your title report should have alerted you to the issue.The payoff the escrow company got from the lender should have alerted you to the problem.Your interview of the seller before you bought the house, should have alerted you to the problem.You calculations on the numbers should have alerted you to the problem.Check, cross check and check again.

They use demand-based pricing like anyone else who cares about revenue. 

High-end properties might demand more customer-focused, concierge-like services, while investors in more affordable housing may prioritize cost-efficiency and risk management.

Rent growth is a function of supply, demand, and interest rates:- I'd ground any forecast by stating I expect national rents to rise on a pace more or less in line with inflation over any long time period. 2-3% per year.

Really only makes sense as @Chris Seveney mentioned if you have a solid, long term relationship with the seller and you are doing a very high volume rehabs

They're very autonomous and don't communicate too much which doesn't demand much of your time. 

Does anyone have a good effective 3rd party mailing company to send mailers direct to seller?

Indianapolis and surrounding areas often offer strong rental demand and reasonable property prices, so you’re definitely looking in the right place.For neighborhoods in Indianapolis, I’d suggest checking out areas like Fountain Square, Bates-Hendricks, and Irvington.

I think the unsuccessful and struggling units who have not jumped ship yet will continue to do so, leading to less supply, increasing demand, and a better year for the successful units. 

Do you include a website on the mailer, or just a phone number for the seller to call?