I use discernment.

Some of these online are posted in resolutions that are too low to discern details. 

You just have to look hard and with a discerning eye, and be willing to buy properties in terrible condition/situations.Second, rents tend to rise faster in expensive markets.

I did a little detective work and it all checked out - the owner had sold 4 other units in various buildings during the past 12 months and from what I could discern he was left only with the 3 in this building.

Decide on the amount of risk you’re willing to take/accept, both monetarily and time.Then when that’s decided consider your options operating within those risk parameters.Now it’s probable that you’ll have trouble being able to quantify your risk, and discerning a strategy, if one exists, to acquire and operate this type operation, let alone rehab and reposition it.Since I sense your not only seriously considering this acquisition, but also quite enthusiastic about it, I recommend that you contact a Counselor of Real Estate (CRE designation) and engage their services to evaluate the property, provide a guide as to pricing, and if appropriate develop a plan for acquisition, rehab, and operation.Hope this is helpful 

It's worth noting that my research has exposed me to numerous courses and self-proclaimed experts, which has left me exercising caution and discernment.

The easiest way to discern a good PM company from a bad PM company is to have conversations with other investors in the area, especially the ones who frequent the REIA's.

The further in you go toward the urban core,  the harder it is to discern best investment areas block by block.

The only way to discern those is to have that deep knowledge of your area. 

I just don't know how to discern whether someone else is also telling me their "best case scenario" rather than the reality.