rental houses with the BRRRR method

[Lisa K Perigo]

I have bought a few rentals over the years and they have mostly been bank owned when I purchased.  I don't know how people are finding something that they figure the after repair value and refinance they are able to reuse all of their original investment.  It seems you would have to be able to purchase a house that after repair would sell for $100k and if it needed $20k in repairs, you would need to get it for $50k to refinance it and pull your money back out of it.  I am curious where people are finding houses for sale at 50% of the arv.  I am not seeing those on Zillow or Redfin.  I hear about wholesalers, but not sure where to find them to do distance investing.  I live in the Portland, OR metro area, so houses are too expensive here for my budget right now.  Although my other rentals are here.