A couple things:Personally, I loathe the arbitrage model.

I’m a couple hours north of Boston but there’s always tons of people looking to move so a longer vacancy or having to lower my rent prices is not even a consideration.

Now you might be like Joe, know rents for a couple of neighborhoods and can quickly estimate expected cash flow from properties pretty quickly (that's what I do as well) but you still need a screening rule so you invest minimal times on properties you will never put an offer in on. 

There are a couple of $100K lots available, and I’m trying to think of alllll of the possibilities.

I’m also from the US so I follow that market and am soon to be involved with a couple of exciting projects in Seattle & San Diego

Here are a couple of developers you should take a look at Trion Properties, their principal Max Sharkansky posts here on BP, https://www.biggerpockets.com/blog/top-5-markets-multifamily-rentals-2019and Feldman Equities out of Tampa (3rd generation real estate family famous for having built the terminals at Chicago O'Hare) who are among the only ones opening up downtown skyrise office buildings to accredited investors.

two things I have learned.  1,200 is a sweet spot for demand, and if you do have a large unit of 2,500 get a couple of them zoned for auto. 

Haha I could spend 10m in a couple weeks.

I've largely stayed away from the "sub-to" buz word, but I have done a couple sub-to flips knowing that I only needed to hold onto them a couple months and I was prepared to pay off the notes if they were called.Sub-to for long-term hold on the other hand has me nervous. 

I actually tried Cherif Medawar's program and have found Licensing Experts vastly superior in a couple of ways.