It was not verbally disclosed and it wasn't until I asked about a specific invoice that it was divulged.I appreciate knowing now that it is a common practice in the industry. 

.#5 Practice, Practice, PracticeWalkthrough potential rehab properties (or find properties virtually online) and practice creating detailed scopes of work, quantifying repairs and estimating rehab costs for the projects.#6 Get Your First Rehab ProjectYou can practice all you want, but ultimately you will learn the most about estimating rehab costs by actually rehabbing a house.

@Stan MaysIt takes time and practice as it doesn’t happen over night.

What are best practices here? 

Why pay the taxes and deal with all the crazy regulations when you can cross over to another state?

It's normally good practice to manage your rental property finances separate from your personal finances, so that's how I'd approach it.

You should, but it's far from common practice.

Whether in practice it is a difficulty, or not is not the point. 

Whenever you are purchasing a deed restricted property that is within an HOA you should review all the HOA documents including covenants, financials, rules and regulations to ensure you understand what you are getting into. 

Start looking at properties you would buy if you had the down payment and do the numbers on them to get some practice at property research.