A market like Boston has a long track record of appreciation in excess of inflation/cpi.  

My thought is that I could reinvest this money into a few other rentals in better markets to gain better cash flow.One kicker of the equation is that I have the loan on the property at 3.1% and since 2018, inflation has been much greater than the loan interest, making me hesitant to give up such a good rate.My goal is increasing cash flow with my investment properties so that I can turn this into a full-time gig.

This is why many buyers choose to pay cash even if they don't have to as they want their cash to be invested indeed, especially given the current inflation.

I’m not sure if the metric has changed much with inflation and rising costs but I’ve repeatedly heard that $200 per door is a good cash flow.

The S&P 500 has that inflation adjusted "average" of 8% annual return, compounded WHEN drip back all dividends, and IF it performs as it has previous 30 years. 

Corvallis is notoriously “anti-building”, a more hyper-inflated market inside of its own bubble compared to the rest of the willamette valley.

You have already seen the downside of a historically zero appreciation market (zero appreciation I define as historically below the rate of inflation).  

While I usually think people have the best intentions, as someone working with you for the first time, it is truly hard not to have the thought cross my mind that the pro forma provided by Jennifer Lucero was inflated by Southern Impression Homes simply to make the sale. 

Currency pegged $2BZD to $1USD (low inflation issues), Official language is English since it was a British Commonwealth, Property rights and laws are basically the same as the US since English based, 2nd/3rd world thus still Rough which I like (has flavor), 2 hour flight from Houston/Dallas connections, land is relatively inexpensive.

Gatlinburg/Sevierville/Pigeon Forge was highly bid up due to realtors pitching inflated revenue projections.