Ive invested in the Boston & DC markets for 22 years now.

It seems most off market deals I've found have been from larger acquisition groups.  

RE isn't the stock market. 

Look for motivated sellers off market and market via cold calling and or direct mail, geofencing, advertising and the like.A good wholesaler is as @Ericka Parrott mentioned, direct to seller, did good underwriting and can deliver an actual "Deal" whether buy and hold or flip. 

Quote from @Jaren Taylor: Quote from @Chris Mason: If you have the ability to market and raise money, then you secure the down payment, and do the normal commercial mortgage process. 

The sales comparison approach is typically done for residential real estate and will be less appropriate and come in under value because there are no good comps, and even an appraisal using the income approach (unless the appraiser is trained to do more complex commercial appraisals) is probably not going to be the most accurate either because they typically use market cap rates and in this case you don’t have good comparable income properties to find the market cap for the analysis.  

I know this is also a National issue, especially in land constricted markets.

Since you're open to markets beyond NYC, you might want to connect with local investor meetups or REI groups in those areas to build relationships with agents, wholesalers, and lenders who understand the nuances of each market.If you're looking to break out of analysis paralysis, maybe start by narrowing down one or two target markets and running numbers on actual deals.

Value: I am paying current market value. 

So, the actual increase to market rent will be much lower.