While a solid investment, I can't believe that prices will increase much more.Lowell and Lawrence are around $500,000 for a decent 3 family and rent at about $1500 each unit. 

It takes a little time to contact them, find out if they want to stay, provide written notice of the rent increase, produce the document and then actually stay on them to get it signed.   

I get it, minimal spend for maximum appraisal.Should I be working with my own appraiser to target exactly what we should do to increase the value.

If your plan is to have renters, generally once they are in place and paying rent, 75% the rent they pay will goes towards debt repayment (which is a good thing and increases your likelihood of getting financing.)

I am also in a population centre growing fast.

Do I try to gradually get him to $700 a month with a 3-5% increase each year?

Looks like I increase the down payment and the initial interest rate, but certainly don't want to pay 10% after that either.

Anyway, my property assessment increased almost 40% from the last assessment (house was completely renovated), but is still $65k under the closing price.

None of the 3 families meet my screening criteria and all 3 rents are under market value.However, there is nothing I can do until their leases are up.I plan to incrementally increase the rents over two years to get them up where they should be. 

On the flip side, each new hand that touches the deal or the loan, increases the likelihood of a mistake.