Nah a remastered RDR would sell like fire even at $60 and likely help a new Red Dead too since if the new game takes place before or features a region from RDR like the leaked map suggests then a remaster would be essential for PS4 and PC players.
I mean RDR has sold around what, 12 million copies to date where the only other game in the Red Dead series was a linear shooter that wasn't that big a hit but now thanks to RDR the audience for the series has only grown. I mean I'm hoping the news isn't a remaster but new Red Dead, however I can see why a remaster could also happen and....I'd likely grab a copy too. lol
It'll sell well but it's still a remaster of an old game, it's not gonna sell huge amounts and not at full price.
Even if it sells 3m copies, it's still gonna make less money than RDR Online if GTA Online is anything to go by. If they delay RDR3 a year for the remaster, assuming it makes around the same amount as GTA Online they will be losing out on $200m on microtransactions alone. 3m*60 is $180m and that's including retailer cuts and what not.
And I'm sure RDR online is gonna make even more money than GTA online does as they will hopefully have fixed loading time issues and have more experience with it now.
As for if it'll help the new red dead sell, honestly I think GTA V already done that lol, I don't think a RDR Remaster will help that much if at all.
Both will sell a lot and individually, both will make more money than just releasing RDR2(3), that's true, but only when you don't take into accounts delayed caused by the remaster which equals a money loss. Most studios source their ports out for a reason because then it is just extra money, but Rockstar doesn't seem keen on doing that.