The asking price is 300k...Portion of sellers pitch:“Enjoy VIP status as an owner and 28 days a year of stay.

So they will gradually be brought up to the qualifying rate. 

The only con is the higher interest rate. 

There's a lot of moving parts here but it sounds to me that you owe them at most the original $150k + a conservative 8-10% interest per year (well above market rate).

Does anyone know how true this is and if mortgage rates will keep going up? 

If it is a normal 70/30 leveraged property, you may end up subject to tax on 70% of your returns anyways - so cost benefit, is that 30% tax free portion worth the high tax rates paid and additional filing fees to get tax free treatment on the 30%?

As far as what I do, I am a funding specialist and work closely with real estate investors to raise capital tax-free by using a specially designed holding account that grows your money between 5%-10% of interest and when it is time for you to pull the trigger on the next property purchase, you will enjoy a much lower lending rate of 3.5% - 4.5% on time for their next property.I've been doing this for 9 years and have worked closely with real estate investors for the last 4 and a half.About my future goals, I am interested in partnerships with other investors within the local area (Bay Area).

And I could have lower income in that window after I semi-retire, before my mortgages are paid off to take advantage of a lower marginal tax rate

After all said and done should be able to refi out get initial investment back and enjoy the returns upon equity.

With no experience you may have a bigger interest rate but if you have good margins on the hose, you should be OK.