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. 

These leads were very unresponsive and may pan out over a longer period of time but the time involved is just not worth the effort.  

This protects your investment and gives you leverage if there are issues.Other Tips:Make sure the lease explicitly defines the move-out date.Conduct a thorough walkthrough with documentation before and after the lease period to avoid disputes.Handling a seller-to-tenant situation can be tricky, but with the right precautions, it can work smoothly.

Also, I believe I saw somewhere that the mortgage won't count against the original owners DTI after a period of time if they show someone else is paying the mortgage.

The other thing to note is that the IRS only lets you have a 401K loan balance of up to $50K over a 365 day period. 

it is the most powerful way to get started in investing, period, full stop.hope this helps

In US tax law, the depreciable lifespan of an asset is defined by its MACRS classification which stands for “Modified Accelerated Cost Recovery System.”Under MACRS, depreciable assets are assigned to different classes, with each class having a specific recovery period.

Then have a 6 month period to convert all old currency $20 and $100 to new currency.  

Period.

You could negotiate terms such as a lower interest rate or interest-only payments for a set period to ease your upfront burden.Lease-Option Agreement: If the landlord isn’t ready to sell outright, consider proposing a lease-option where you continue renting for a set period with an agreed purchase price.