With all of that said, I'd say your idea is basically a step toward investing in unsecured debt (on the spectrum of secured to unsecured).

By less expensive area, I'm guessing you mean the cost of housing in that area is lower, not buying a house in a rougher area (the latter is not a good idea).Start by talking to your bank to find out how much you are qualified to get for a mortgage. 

You can get a good idea of price per sqft then apply that to your property.

Meanwhile, bookings well into the busy season continue to be made.I have NO IDEA how to play this 'game'.

There’s heavy competition, prices are tight, and most properties are either overbid or don’t leave enough margin after rehab.I’ve been watching local county auctions too, and while some of the numbers look promising, the idea of buying my very first flip with cash, without walking the property or inspecting the condition makes me nervous.

There is still so much land and my dad and I have been talking if it would be a good idea for me to invest on building another house on the opposite side of the current property because it leads to a main street.

Meanwhile, bookings well into the busy season continue to be made.I have NO IDEA how to play this 'game'.

Just looking to get some feedback from the community on if this is a good idea or not. 

In the meantime, it is best to prepare for when the note comes due as you are doing.One option is to find an appraiser local to you that will do an appraisal consultation and they can give you ideas as to how to improve the value of the property ahead of time. 

Open to ideas or suggestions too.