I have dabbled in real estate, but never heard of brrrr before now, and transparently never did much research outside of knowing that property ownership was a way to reduce my taxable income. 

Do not place yourself into a position of needing to sell in a reduced value environment. 

We had good capital gains on our first new property so we were able to inject that in our current primary residence reducing mortgage amount.

My question is, do I just use the heavily reduced price I was able to purchase it for since it was vacant, and then the material cost of what I renovated plus what things I did contract out, even though that basis would be way under what the other renovated houses that sold near me per SF sold at, or are you able to use similar comps to determine the depreciation basis?

A lot of what you're paying for is free / reduced with Baselane. 

@Mordechai ChaimovitzGreat points made above along with what @Daniel C. said referencing @Tom Shallcross's post on another thread.The context and variables for each individual investor will vary but many people are comfortable with getting a 2-4 unit that will reduce their out of pocket expense compared to their previous rent with the intent to do rehab and raise rents over time.

Beside investing their own cash on the same terms, the sponsors return should be heavily weighted toward “carry” (receiving the bulk of their return as sponsor in the form of an interest in the property rather than cash) with that carry subordinate to the investors receiving their investment returns PLUS a minimum annualized return.

When it comes to analyzing properties, I’ve developed a specific checklist to make sure the home fits both resident needs and operational goals:Square Footage: Ideally, at least 2,000 sq. ft. to ensure enough living space for residents and staff.No Stairs or Pools: It reduces liability and keeps the home accessible for everyone (this is just my preference).Corner Lots: I love corner lots because they often provide extra parking and outdoor space—both of which are critical for families and visitors.

Paying off rental mortgages increases monthly cash flow but reduces liquidity, while investing in hard money lending offers high returns but is taxed as ordinary income.Buying a multi-unit rental provides tax benefits like depreciation, while purchasing a business can yield strong profits but requires active management.

Especially as it relates to being able to rollover IRAs and old 401k money into a Solo401k.Self employment allows you to contribute large amounts to Solo401k to reduce FICA taxes.