I would not start investing, creating businesses, or doing anything in life based on a unicorn example, whether it be real or imagined.I would look at the industry from the top down, figure out what realistic margins are, and see if I can gain a competitive advantage or beat general market returns by a few % points.  

If you have an HOA that has 3 or 6 month minimums I believe this could be a viable route but a 30-40% lease up fee for a single month alone would likely devastate the profit margin. 

You need to have good margins otherwise it's not worth investing in the deal. 

I'm a responsible investor who takes good care of my properties and it sucks seeing these tax rises hurt the margins. 

Wholesale will flip themselves if the margin is good enough.3.

So I’ve had this happen twice in a relatively short period of time and I’m a bit confused about it.The first time it stood out I went and looked at a property and I told the wholesaler I could only give X and they guilt trip me saying they only was making 5k as it was.So we did an assignment of contract and I agree that they needed to make something and it was a marginal deal for both parties.

However, insurance expenses in CA aren't going down anytime soon so that could affect your profit margin.

With cash you canmake higher margins per deal because you have less holding costs.

I will add that oftentimes the fixed costs with installing any kind of pool (fence, pump, permits, excavation etc) are so high that the marginal cost of a plunge pool vs something more standard is relatively small.

Precast concrete is a low margin business overall but seeing as this is very special, it would be more that simple stock tanks and the like.I would go for in-ground all the way.