The one factor I have yet to see anyone consider in these thought provoking comments is unemployment.

That being the case, the usual HR Block "W2 factory" processors haven't been very helpful.

Intel is a great example, who is building the largest chip manufacturing plant in the US right here, and it will be a $20 billion dollar investment that brings a few new thousand jobs.https://www.dispatch.com/story/business/2022/01/21/intel-ohio-building-computer-chip-factories-licking-county-jersey-township/9173472002/ Another example of economic growth is the upcoming Ohio State University Wexner Medical Center Inpatient Hospital which is a 1.9million square foot hospital that will bring over 800 new beds and a thousand new jobs. https://abc6onyourside.com/news/local/new-osu-hospital-expected-to-transform-health-careHere are a few more recent investments https://www.10tv.com/article/money/business/hydrogen-power-company-hyperion-bringing-700-jobs-to-columbus/530-25907aab-5517-4661-a9f3-d2ed2d5be6b0 https://news.wosu.org/news/2022-02-08/rumpke-to-build-50-million-recycling-facility-in-columbus Check out The Complete Guide to the Columbus, Ohio Real Estate Market which goes through the Columbus, Ohio market in depth and will give you a better scope of where the highest levels of growth are taking place and where to look to invest.

Another  factor is low interest rates now make loans attractive now vs later.

One factor is the state where the sale occurred, whether the sale transfers all the liens to the tax sale buyer, and how good is the notice. 

Not too many people can brave the world of Tax.The material factor is important.

Lots of factories building or looking at Sherman. 

Also, many of these investors have Insider knowledge of an area (ie. a major factory is coming to the area, and folks know that the demand for real estate will go up in a few years)Or, Michigan just legalized weed, so we can assume that their market prices will go way UP over the next few years, like the other states did.

The limiting factor is that some states have not adopted the legislation to form a Series LLC within that state.For example, if I form a Texas Series LLC and have a property in Florida held by one of the "child series," then if there is legal action the property will be analyzed against Florida's internal liability shield.

A huge factor is experience, though.