The rule multiplies the ARV by 70% to calculate the value of the property before repairs.

There are other metrics you can use, gross rent multipliers and price per sf come to mind!

To ballpark a property bought in the last couple years you could divide yoru price by the last buyers price and then multiply that number by their taxes.

Can't divide or multiply by 0

You multiply the mileage rate times the assessed value and this will give you the amount of taxes for each.

The difference between single-family and multi-units is multi-units appreciate in value when you increase rents and single-family homes do not increase in value when you increase rents.So, if you own a 10-unit property that you can sometimes purchase for the price of a few single-family homes the numbers work like this:10 units x rent increase of $100 per month = $1,000 per month more rental income = $12,000 per year x 18 Gross Multiplier = $180,000 you increased the value of the property by increasing the rents and you cannot do this with single-family homes.Then, suppose, you have a cashflow of $400 per unit when you purchase the property.

Multiply that by nine years remaining and you get $518.40That's what I would charge the Tenant. 

Once this is all completed, take that model and multiply it across another 500 homes and grow it that way.

You said you had several years worth of returns...so multiply that few hundred dollars, and the price you got seems reasonable to me.In addition, you provided spreadsheets instead of some standard accounting format (QuickBooks, for example), which just adds to the time/complexity of the accountant's job.If he's good, he likely saved you more than what you paid him.Lastly, and I don't mean this to sound snarky, but you ended by saying that you might as well have done the taxes yourself -- if that was an option, why did you have several years of unfiled returns?

Multiply it's ARV by .75 and make sure you're under that with purchase price and rehab