I own a few watches but I only think my Breitling navitimer b01 and Rolex Wimbledon are heirloom pieces.

Any watch can be passed down. Price is irrelevant.

Im still wearing a Swatch i received as a gift from my sister 12 years ago.

For me, the sentimental value outweighs the intrinsic value.

That said, as a resident of 3rd world country, any watch exceeding 1k USD (about 2 months wages in here after conversion) starts to feel like a forever piece. For me at least.