I bought a terrific LZ II, Bob Ludwig pressing, for 6 bucks when on vacation a couple of years ago. Hole-in-the-wall store.
Port's records are rated by his personal listening so they aren't simply cleaned and visually graded. It all takes a terrific investment in time (which is money!). The records are curated.
So, if you have the money and you've got your money-back guarantee, then go for it.
Me, I'll clean 100 six dollar records before I plunk down 600 dollars for one!
Paul