At this point, I can bide my time and wait for the seller to evict the tenant.

I have a tenant up stairs who is happy that I’m intative to any issues that comes up like her water tank that kicked the bucket she only had to wait 24hrs before it was up and running.

Best thing would be to call and ask the planning department and ask them what their current wait time for permits are. 

We could try to structure an offer contingent on the certification but I don't think the sellers would be willing to wait.

Should I wait out this sellers market and buy during the next down cycle?

You are going to need to have 20% down, plus closing costs, and you will want something in reserves, a few thousand for the unexpected such as a vacancy or unexpected repair. 

Hey, wait a minute....... isn't that the same return as the Property itself?

Stick to your guns and wait for a tenant who can pay the move costs up front, in full.

I was curious about this myself because the phone is what I use the most when I am out looking at properties and being able to use the calculator through the app would be so much better than trying to go through the browser or waiting until getting back home.

When the property is vacant, you have to cover taxes, ins, loan2 - Property Management:  If you are going to have a PM down the road, and they cost 10%/month, use 10%/month in your analysis.3 - Loans:  Hard money cost (points and accumulate interest) is a hard cost...not a cash flow cost4 - ...and 12 years is a long time to wait for your cash back.