@Jaron Walling the example was purely hypothetical just to make the numbers a little clear and easier.

One lender has told me I can put down 10% on a multifamily that I am not living in (so pure investment) and interest rate is 4.5%.

I am constantly battling my personal checklist vs a purely investment driven checklist for my next property since I plan to live in it before making it a rental. 

While I'm purely in the thought exercise mode right now, I'd like to delve a little deeper and explore how to structure a deal like this.

It is a fantastic spot for STRs, but because of all the growth in the significant increase in list prices, it just does not currently make sense (at least not from a pure investment perspective).

One is based purely on the appraisal value and your finances.

That being said, you can skip all the above steps, apply the 50% rule (which is fairly accurate) and find that this deal is going to fall short of just about every return metric.The only reason to buy this building would be because of future appreciation, which is purely speculative and probably not a wise idea.Good luck!

We also buy pure rentals.

Three full 8 hour days, lost from my regular job and everything else, of pure sales-pitch infomercial up-sell B___ S___ with nothing useful anyone could take and go start making deals.  

There have also been some purely informational speakers that have been excellent and well worth the cost of membership.