Our Grade A materials have 2 yrs of light use.

There is no hard grading system on investment properties so “Class D” would be a subjective term but ideally it would refer to the “state/condition” of the property, “quality/affordability” of the tenant base and the “rent/income” it could provide.  

I can share you my neighborhood grade map though to help identify different areas.

My father in law a 7th grade drop out self made millionaire used to say "KISS" keep it simple stupid..... he died 3 years ago I sure miss him.  

I'm not taking significant risks with new projects at the moment either so I'm not in a huge rush but also don't want to lose money as time goes on.I decided to build this property in an up-and-coming area (B- grade) with an estimated rental value of $1800-$2000 per month.

I'd be happy to send you a graded map of the area and a list of useful contacts.

Besides that, I would never go off any seller ever in trusting the grade of a septic system, the township is your best friend when it comes to figuring this out. 

But per lot it will cost roughly the following:$1,500 Electrical poles, meter installation $2,000 water taps and connections$5,000 grading and land prep$8,000 septic installation (assuming a 1:1 ratio of homes to 1000 gallon septics)$5,000 down payment on each home ($700-750 / thereafter per unit)$21,500 total set up x 17 = $365,000Ongoing expenses after development would look something this for POH model: $12,750 a month in mobile home mortgages (17 x 750 for PITI on each unit) $1,900 a month in land mortgage PITI (house) $3,000 a month landscaping$2,000 a month in reserve emergency fund$2,200 management$21,850 a month total expenses $262,200‬/yearOngoing incomes after development would look something this for POH model:$27,000/month ($1500 x 18 {17 mobile homes plus house})$324,000/year324k-262,2k = 61,800 net pre-tax profit or $5,150/month.Opportunities to reduce start up expenses: Bulk deals with the government or contractors for doing all the work at once (electrical, water, land grading, septic) Trade free rent for someone to mow and landscape (turning a $3k event into a $650 event every month).

I'd just get rid of the old ties and have your landscaper level out that grade a little.

Grading/ sewer/ septic/ permitting /any subwalls ..