Desperate people will eat it up though thinking it will help.

HOA and management eat most of my profits...The house has a 7.25% interest rate.

Don’t the closing costs from buying and selling an investment property eat up all the appreciation (and mortgage principal paydown)?

I eat that stuff for breakfast.

Price materials and labor cost will depend on how large of scope of work but a good company is going to be around 3500 a week plus cost of over head we also pay 30% tax on our income also like you guys but if you anticipate 4 week rehab well be ready for minimum of 14k in labor +14knis low end in my opinion... now I'm currently eating my lunch on a rehab from hell but it's gonna be a work of art from where it came from... this was the worst of the worst in my career water damage to all structural raised the roof on a horrible addition and did it correctly. 

It is a huge ticket item and can eat ~30-40% of my reno budget.Today I did a walk through with plumbers and contractors.

I portrayed it as if you want to "eat your young" so to speak and just consume the principal, but if you reinvest the funds pulled from the properties, you essentially transfer all of the equity from the properties to something else tax free (assuming you keep the properties).

While a business owner's job is primarily to focus on revenue, you also have to make a basic effort to control expenses and keep things from eating up 1,2,3,4% or more of gross income.

Once you move, you'll have to hire someone to manage it for you, which will eat into the income.

But keep in mind that things like closing costs (where you have to close twice - once to buy the flip and once to sell it) may eat up $10k of that profit before you pick up a hammer to repair something.