Only way to get a blue sub mariner is to get a white gold version. Steel sub in black or green $4k. Steel and gold $12k. White gold $20k. Diamonds are even more.
Just avoid 'catalogue' watches like Bell & Roll. $3k for a $200 watch
Edit: I'm still on the hunt for a meters first red sub in unrestored condition. I'd wear the shit out of that watch!