I think "raids" will draw in a some of players that have stopped playing osrs already. New content usually brings back quite a few for a month or so at least. Not going to argue with you about the gold rate though, you are spot on.
The seller has really good feedback and reviews so I would assume they are real, but I am always somewhat skeptical when I see those generic stock photos though.
Without the pets the account would be pretty cheap tbh. Those pets on the other hand, I would say it is around 80m give or take.
The rng gods must love you.