If you're not currently listening to books educating yourself, I'd start today.A few I'd highly recommend...Buy, Rehab, Rent, Refinance, Repeat - The BRRRR Rental Property Investment Strategy Made SimpleFLIP - How to Find, Fix, and Sell Houses for ProfitThe Book on Flipping Houses How to Buy, Rehab, and Resell Residential PropertiesThis book is not currently available on Audible but a must readThe Book on Estimating Rehab Costs - J Scott

When interest rates are peak high I started my first investment and was able to cash flow !!

Rates will be in the high 11s-12.5% Range 

At this point I will have pick up about $450K in appreciation after sales costs, but that is before taxes and I am in a high bracket. 

The first people that lose their money in a downturn are those that are lending at insanely high LTVs without adequate underwriting experience including determining if the borrower's qualifications based on credit/character, capacity, and collateral.  

There are some "lenders" out there who "do" incredibly high leverage or 100% financing, but be wary of these as they often try to renegotiate terms before closing/run out of capital/go bankrupt.

However, due to crazy high rates and housing inflation, I still live in this house.

Can you define what High IRR means to you?

I've you've already used $315k, you have $451,550 left.https://www.veteransunited.com/education/tools/va-loan-limit...Even though $515k>$451k, You CAN still use your VA loan on this duplex (and I highly recommend it).

The shorter the prepayment term has an impact on increasing the rate.4.