Ask your realtor to check if expansive soils are common in the area. 

@Christopher J Lemmon In my area, where the soil tends to be sandy and will drain well, we budget $35,000 and hope for $20,000 - $25,000.It's hindsight now, but when writing an offer, I always include a contingency that lets the buyer either get a price reduction or cancel the sale based on the outcome of the septic inspection. 

Is it known to be particularly soft soil in the area?

My ‘line in the sand’ is that I want a smaller 800-1000sf house to cash flow at least $300/month for it to be worth it for me to buy.  

Believe it or not, there is land maintenance, mowing, clearing, cleaning, fence repair, erosion and drainage, and soil conservation.

My beach STRs that are 100' from the sand is 3 hours drive from ~20 million people (Tijuana, San Diego county, Orange county, Los Angels county, Imperial County, Riverside county). 

The maximum size per system is 5k gallons, and we have class 3 soils.

There is a 10+ unit building that was under contract and the deal fell through due to DEC records of soil contamination from a previous nearby gas station leak. 

There are so many different options and it is based on how much you can afford and what you want to do.When I had to do mold remediation on my house after Hurricane Sandy,  hired a professional mold remediation company.  

South Salt Lake or Sandy?