hyper forcus on one area and go under contract directly with the sellers.

Quote from @Clint Miller: Seller financing opens up great opportunities for real estate investors, but coming up with the down payment can still be tricky. 

You lose because there are many other suckers out there falling for the same line and sharing the same low-quality leads that don't translate into sales.Do the math.

It appeals to desperation on both sides of the transaction, which also makes it a great online class to sell... 

Others have hit it on the head.

Start to evaluate deals based on the income approach and you'll do much better long term investing. 

A monthly fee (typically around $5-20/mo) is added on to the payment.

I could be wrong or out of line, but I feel like this is a field where you really need some good expertise/experience to know how to address the variety of crazy situations that will come up.

I was planning on doing a BRRR.

To adapt, focus on refining your ARV and repair cost estimates, explore off-market deals, and consider creative financing strategies like seller financing or partnerships.