I'm considering purchasing a condo or a small SFH in the Oceanside/Carlsbad area as an investment property and renting it out on a short term rental site like AirBNB. 

Purchase price: $785,000 Cash invested: $156,000 Short term vacation rental in Panama City Beach.

Quote from @Yaroslav Shtogun: Hello Community,I am seeking advice on the following real estate situation:I’m in the process of purchasing a double lot property (100x100 in an RS-50 zone) that includes a 1,200 sqft wood-frame house and a 640 sqft detached garage.

Why do you think purchase contracts are so long and have such small print?

As long as you purchase at least as much as your net sale. 

If that investor hadn't planned it carefully and re-invested that money into the property or even the purchase of another then a recapture fee would hit them hard. 

With that in mind, I’m considering purchasing four rental units over the next four years to build a stream of income that could help supplement my retirement by age 68.The challenge I’m facing is that the deals I’ve come across so far don’t make financial sense.

So you wouldn’t get any depreciation on your new purchase assuming you only spent the $450k.

I purchased then started the remodel before trying to rent.

Because I had already purchased  the house building courses I got a nice  discount  on thw course I wanted.