shortage has always been artificial IMHO, ADs just wants you to spend more in store to get the desired pieces.
Subs and Explorer are a good start, 50k would allow you to purchase immediately at the Grey market but at mark up prices. Unfortunately, I doubt you could get a stainless steel rolex by walking into an AD.

Have you looked at other brands? or does it have to be Rolex? It looks like you going by what is being recommended to you rather than experiencing the timepieces in person.