From my analysis—even with very conservative numbers—it looks like a cash cow.

I would venture maybe $20k total, conservatively. 

My current plan is make a conservative offer, pending financing so that I can get those 8 and have enough cash flow to pay my HELOC while not compromising the flip.

It changes the family dynamics, and not always for the better.

If this was me, I would leverage my equity into a commercial office/retail/industrial multi-unit or multi-family property.

I'm a very conservative investor and may look through a hundred deals a month, and at the end of the year only invest in 4-5.

I have gotten a seller's credit for my 3 existing units but to be conservative, I will assume I am paying full closing costs here.At the moment, I have ~$25k in a HYSA and expect to save another $10k from my W-2 before I start putting offers in.

If you're looking to transact faster than that, then your only option will be private Buyers.Another alternative, other than the ideas mentioned above, might be to sell part of the land into permanent conservation. 

While the numbers they provide might make sense under specific conditions, it’s always a good idea to apply a more conservative approach to ensure you’re prepared for the unexpected.For vacancy, the tenancy averages they’ve shared (3.8 years for C class and 6+ years for B- class) aren’t out of the realm of possibility, but I’d treat them with caution.

It really forces the syndicator to be more conservative in their underwriting.