Markets are unpredictable, so it is hard to speculate what something will be in the future.

Don't get me wrong, I realize that investors shouldn't speculate, but we have lived in the area for a while and the growth (population and commercial) has really increased.  

It was speculation by people who did not have a clue as to what they were doing.If you are not convinced that you are offering the homeowner a service that is in their best interest, then you should not be working with that homeowner.

That I understand, but your supposition that this will allow higher equity is not necessarily the case.Most, if not all, lenders will use the BPO/appraisal to set the lowest price they are willing to accept.

Here's the problem: Portland is so hot right now that investors are competing with other investors (normal), home buyers (even for larger multis), STR investors (probably the only way to make big money in the current rental market), developers, speculators, etc., etc., etc. 

Problem is finding a multifamily with a reasonable GRM, since speculating in gentrifying areas is rampant, even in the tougher old hoods.

Zachary Stoll Paying $285k for $2,750 a month in rent is not great - only play is banking on appreciation which is speculating.

Also, are there any speculations on how much cash I would need to start?

Predicting how much a tenant will pay, how much in tenant improvements will be needed, and how long the space will stay vacant before finding that new tenant is speculation when you're talking about a lease that won't be signed until 2020.I know a guy who owns part or all of about 90 retail projects.

Its purely speculative, and real estate investing isnt: You know pretty much what you're going to get out of it.