We vetted a  handful of "turnkey" companies and REI Nation was the best in terms of reviews across multiple sources. 

I filled my own taxes for multiple years for multiple LLCs in multiple states.

Let's assume that the neighborhood is a C class and the median income of the city is greater than 3X of the market rent.Here are some of the considerations I've come up with so far:- Units are in need of renovation and capex is too high or not available- Unit quality is not the same as market - Seller is worried about losing tenants due to increase- Vacancy rates are high or filling units have been difficult- Rent increase would take multiple increases over multiple lease periods to get to market rate if seller is trying to retain the same tenant- Seller inherited property and just want to liquidate- Seller needs to liquidate quickly (financial burden, sickness, quick exit from land-lording)It seems like I might be missing a warning sign about a deal if they are selling with current rents that are under market; but again, this seems to be most of the properties I've underwritten.And in the same vein, what should I be worried about when purchasing a deal with under market rent with the intention of raising them after purchase. 

For example:How well does in-house counsel adapt to different jurisdictions, especially if we’re managing properties across multiple states?

(Interesting that I just came across this old post for the first time.)I’ve used Jerry Feeney’s e1031xchange multiple times.

Quote from @Mitchell Gunlock: Quote from @Cliff Benner: Looking for Tips on how to find places that have multiple cabins or additional dwellings on a property that I could live on and run.

Investment: $200K; ROI: 26.29%/year; 10-year equity: $1.1M; Total cash return: $1.2M. 10-year equity multiple: 8x on $200K investment.

I went from buying multiple properties per year to doing nothing 2022. 

Look at the results in multiple ways and over different time horizons.

However, you can likely sell all the properties in the required timeline to do the 1031k, although that will take some effort/cooperation between multiple buyers/brokers, considering the separate markets.