My take on it is, most important thing to know about buying records is yourself. Are you a sound quality buyer? If so then marketing schtick like original analog master tape is just that, marketing schtick. The luck of the draw in terms of the quality of the individual pressing you happen to get has far more to do with the sound quality you will hear than anything else. Are you a record collector? If so then you will be happy to have what no one else does, the rare original test pressing of, well whatever. The one with the accidentally printed upside down cover, I guess. Are you a fan? Impulse? Buy the hits follow the crowd?
Whatever it is the more you are honest with yourself the better luck you will have.
If you are a sound quality buyer there really is only one source for records of guaranteed extreme high sound quality- Better Records. Not cheap, but they are the only records I know with a 100% money back guarantee if you don't like the sound. Which they are able to do because unlike all the others they actually do have the sound quality, original master or no original master. They don't care. Only thing Tom cares about is how good it sounds.