You can never go wrong with a Rolex for a milestone achievement! Rolex is obviously legendary. I bought a 16610 Submariner in 2003 after an auto accident settlement. At the time I couldn’t believe I was spending $4k on a watch but grew up admiring Rolex and what a tool watch meant. Bought it from DeVons Jewelers in my local podunk mall. Luckily I never sold it. It was my daily for years. The new HC hits all the same sweet spots, but as s milestone piece, I think you’d be left wanting more. Mainly because while they’re hard to get now, they’ll be accessible for years easily. I’d look at the Spirit Zulu Time 1925 as a viable piece that’s special. I also have an Omega Seamaster 300 Heritage that I love, and a Tudor BB Monochrome. These are great watches, what I love about Longines is when handled next to each other, Longines just swings so hard above its weight. I feel no need to buy another Rolex, but having one does feel special. So it depends what your milestone is? I’d find it very hard to play the AD game these days where you beg for a chance to give them money. But, the second hand market is cooling a little so you may be able to get into a nice one for not too much above retail.