I'm managing D class properties with a property manager and am making a profit. 

Quote from @Brandon Foster: Hello Ryan,STR is do able in the north county area but there are a lot of rules and regulations.The city of Oceanside right now will not allow anything STR unless it’s west of pacific coast hwy.This is changing a lot too so you need to be aware of that in your plans.Carlsbad is super strict too but there are some condos that are still available to do STR in.Medium term rentals are as safer bet but way less profitable.

As a broker in a wholesale market, I "buy" a loan from a lender at a discount and mark it up for my profit.

That data would be sales price after remodel (the true numbers some agents really don't have the experience to be comping the property), the days on market you will experience (this is great info because you want to recycle the money quickly), and resources to sell the place fast not slowly which you do not want this because this could put your holding costs extremely high and push the property to little profit or no profit. 

That profit will increase over time and improve your return. 

In southern Florida I fund and profit / loss is 50/50.

Stationed there almost three years, sold with profit and tax break for how long we lived in the house.

Make sure both parties fully understand and agree on:How profits/losses will be split Who is responsible for what (e.g., repairs, management, communication with the seller).Exit strategies in case things don’t go as planned.When you do find the right partner make sure to create a joint venture agreement that outlines all of this clearly.

From there every 20 point increment affect pricing differently.

Overall, it's been pretty profitable.