You mention you have no experience in these types of parks and your first deal you want to take down 100.When I was working for a GC we did a condo project for a developer who never developed a building before and he sold his company (it company) and used the entire amount to develop real estate.He ended going bankrupt because his inexperience with his experience and his designers and every mistake they made was multiplied by 150 since that is how many units there were.

And the imputed value will be used - take the tax assessor's assessed value and multiply that by the leveling factor that the PA Dept of Revenue publishes for that county for the year of the transfer and you get the imputed value.

I prefer MFH versus SFR because I'm able to multiply my cash flow while keeping my CapEx relatively small.

I believe the one good thing about that spreadsheet is that it can be adjusted by the State you live in. because costs are different in every State the estimate sheet i believe is based on a multiplier for the corresponding State, as most cost estimating books are based. that program does break down a lot of information for you and i think it is a good program, one thing you may want to check is if the program updates every year with current multipliers for the States ( program is probably based on a starting average value for each thing and then the multiplier changes as prices for materials change) and you want to make sure it does that.

The number of people on the auctions has multiplied and there is much more competition nowadays. 

Here's my calculator:  Determine what your weekly rent is going to be on the property and multiply it by 26. 

Not only does the appraised value get multiplied by 6% rather than 4%, but the millage rate is significantly higher as well for investment properties.

So to calculate the rent to home value such that I can apply the 1% and 2% investment rules of thumb, I multiply by 12 and then invert.  

To do this, take the purchase price and multiply by 11.5%, that will get you close to assessed value.

@Joshua D.Josh: Come up with a number you want to live on in terms of cash flow then multiply it by 1.2 times.