As Jason mentioned, you should max out the Liability on the underlying policy (dwelling/Fire form in Personal Insurance or General Liability form in Commercial) and then add umbrella coverage above it.When you insure the unit, you need to know what parts of the building your unit owns and what are owned by the association (common elements). 

In MN the Hoa actually owns the lakefront of my property because they want to ensure equal access and avoid any environmental Fines.  

We are also open to other areas, as we plan to utilize a property manager to handle the day-to-day elements of the home.We currently have $80K saved, and can probably get to about $135K by May of 2022 through various income streams.

Here is a list of due diligence item I use on my MHP investments:Check zoning and permitting compliance (city zoning)Check local law compliance (with Sherriff and/or Police)Search City Council minutes for any adverse mentionsCheck with State Department of Public Health's Division of Community Environmental Protection (CEP) for compliance violationsCheck with property neighbors for any disputes or pending legal actions Water - Check with water provider for any open or recent issuesSewer - Check with Sewer provider for any open or recent issues or complaintsElectricity - Check with electricity provider for any open or recent issues Rent roll with space number, name of resident, move-in date, renter or owner occupied, number of occupants, monthly rent, additional charges, current balance due and any relevant notes about the residentList of capital expenditures for the last 3 yearsGet last 2 years of Profit and Loss statementsGet last 2 years of Tax Returns for the LLC/Park12 months of Bank Statements for the LLC/ParkCurrent Accounts receivable statementsBuild proforma for next 5 years using rent roll and expensesGet owed taxes to City/County/Local govGet Insurance Quote of commercial liability insurance2 years of utility billsProperty Tax bills for last 2 years List of park owned home including copies of “rent to own” or sales contractsGet list of vendors and contract status for each vendorTalk with on-site property manager regarding issuesConduct Onsite Property Visit with property managerSpreadsheet detailing who pays all utilities including water, sewer, gas, electric, trash, cable, etc.

Even after paying for a years of insurance, phase one environmental, appraisal and so on...we ended up only having $2100 total out of pocket to close it.

Or are there environmental requirements. 

As you mentioned, there was an element of both luck and a good deal (though it's a 200 year old house, so the major improvement pains are yet to be seen...the house was greatly maintained and updated by the former owner, thankfully). 

@William HinscheThe most expensive items I’ve seen are:Structural ItemsRoofsFurnace/Air ConditionersLead Paint or any environmental issue

, doors off hinges, broken windows--unreported and just left broken and open to the elements, heavier wear and tear on flooring than class B, large secret dogs that they are babysitting for a relative in jail for unpaid parking tickets, cigarette smoke smells indoors, broken shelves, home-made (crap) repairs on things, dead cars on the property, dead cars up on blocks on the property, piles of old bald tires, etc...Not all, but some. 

Has anyone purchased or sold a property with DPS (Downgradient Property Status) filed on it, because of environmental contamination from an upstream property?