You'd have to be willing to spend around $700k for bigger buildings or take your $350k budget to harsher neighborhoods and hope for quality tenants.  

Only problem was the land was under active railroad tracks, and the remainder was wetlands.Speaking of which I have seen wetlands, flood plans, land protected by easements, or some other reason that the property can nt be built on, sold at tax sale.I've seen property sold at tax sale that were toxic waste sites, including Super Fund sites.I've seen a chrome factory sold at tax sale abandoned by the company because of toxic chemicals in the ground.I've seen former gas stations, dry cleaners, auto repair garages, and other toxic sites sold at tax sale.All of the above either have ZERO VALUE or NEGATIVE VALUE, welcome to the wonderful world of Tax Sales.

I personally have spent more than 25 years in the petrochemical industry and have had to wear fresh air respirators and full chemical suits in numerous pressure vessels and towers that have had toxic or inert atmospheres that were considered IDLH "Immediately Dangerous to Life and Health", and I still don't have the time nor the desire to worry about how someone's hair or lack thereof would impact whether or not I could work for or with them.

If you aren't shoving hot grease down your drains and/or toxic chemicals and/or sanitary napkins, you can go for years without having to have a tank pumped.

It seems that Vinyl floors are highly toxic since they are made of PVC, Laminate flooring also toxic since they have formaldehyde and carpets are also toxic since they have fire retardants and stain resistant chemicals.

And Septic is not a big deal as long as it is maintained (you/your tenants must never put any bleach or chemicals down the toilets, tub or sinks). 

I work for a chemical manufacturing company and have owned a sfh rental for 2 years. 

Also their closing costs was around 4%.Check out Shawn Huss at Chemical Bank.

Re a nail salon next door: The toxic chemical fumes from it would drive customers away in short order, and probably make the other side uninhabitable.

I just got pre-approved by Shawn Huss at Chemical Bank.