For the 10 year period spanning December 2014-2024, single-family prices in Austin nearly doubled, yielding an annualized appreciation rate of ~9.4% in that period.

Lenders or investors who have short lock up periods but have years of experience feeding their business with new capital would give me more comfort but anyone who is just starting and is promising a rate of return or return of capital in a set period of time would be alarming because they very well could be reliant on fresh capital to make good on that promise and that usually ends poorly.

Just a heads up this will not be tax free, it will be a pro-rated exclusion.

I'm curious what lender would take something that can have swings of 50% on a weekly rate as collateral?

Everything in house.

Also look at those Vrbo and Airbnb calendars and see how full they are and what nightly rates they are getting.Should be easy from here to see if a new property would pencil in or not. 

If you can afford a higher payment, a 15-year mortgage saves on interest over time.For the down payment, aim for at least 5%, but if you can put down 10-20%, you'll avoid PMI and could get a better rate.

If you are considering working with them, I strongly advise you to double-check the provided rates and terms carefully.During my loan process, I discovered that they had added a yield spread interest without informing me. 

I have to clean your house?

Variable cost and CapEx are where I see most investors make errors on their Pro Forma.