BP has built a great selection, all of them worth reading and that will help you build foundational knowledge.To answer this one: the words from old school investor Dolf De Roos "seldom sell" and you will find a lot of post on BP from people who regret selling properties in the past.

It’s a 2/1 750 sf house built in the 1920s with  a concrete wall foundation and partial basement.   

It’s like a built in test. 

We're exploring creative ways to provide him with the cash needed for the down payment while avoiding triggering a taxable event.One strategy we're considering is purchasing his future primary residence ourselves, making the mortgage payments, and then, once we've built enough equity—comparable to the appraised value of his rental properties—transferring the title to him as a form of exchange.What are your thoughts on this approach?

It's one of the hottest markets in the US right now with so much population growth, job growth, and companies moving/developing here (26B Intel headquarters being built here, 68K+ enrollment in Ohio State University, Amazon, FB, Google, Honda, Nationwide, Anduril, etc.).

They sell an older inventory unit, get all there appreciation and equity liquid, and use it to secure 2 new built units. 

Over two years, I built up 12 doors, which now generate about $100k in net income annually.

I also grew up in cupertino when Stevens Creek and Hwy 9 were still gravel and 280 was not yet built :)  I worked for a syndicator in the late 80s and we had projects in the foothills and did the last phase of Lake Wildwood.. 

•Set up notifications when a listing matches my criteria.Has anyone built or tried something similar?

@Vinny MuliIf you have equity built up, can you do a cash out refi?