I'm reasonably proficient reading legal contracts, but have no particular experience deciphering notes.  

(very skilled or proficient at something.

Do this:1) Bring the big guys deals and don't be greedy asking for a 5% fee like everybody else does.and/or2) Become proficient at underwriting and offer to help that wayAll big guys are looking for deals and I don't know anyone who couldn't use help with tedious number crunching.Will these strategies take time?

I would definitely use the higher estimate to negotiate with, as well, but if it comes down to you having to cover some or all of the cost, then at least you should have 2-3 estimates to determine how economically and proficiently it can be done.Foundation issues can be very scary, and I have had a handful of buyers walk away from a deal because of it; but I've had more continue on because they know it is a crap shoot trying to find any property that is immune from this issue in Houston.

I know how I would structure it, but your needs may be different.There are two main options for seller financing:A note and mortgageA Land Contract, aka Contract for Deed Both would accomplish your stated goal, however they each have very different tax consequences, and the foreclosure costs and timelines can be very different.I'm assuming you have vetted the buyers, verified income, checked credit and everything else you need to do before completing the transaction.I know an attorney in Cincinnati who is very proficient at these.

I've gotten proficient in the rental calculator so I thought the BRRRR strategy may be good on new construction but was a but confused by inf% for cash on cash.

Becoming proficient takes time and putting deals together takes skill which takes time to develop.

Once you are proficient in something, for some odd reason, one feels that no one else can do it better than yourself.

I founded RealData in 1981 to provide usable, affordable software for investors and developers who weren't necessarily proficient with computers.

At 19, you need to know that whatever industry you choose to work in, education will be vital, it is a never ending quest that requires you to maintain proficiency and to stay current with business requirements.