What's the point of always "changing" the tomestones?

[Vaer]

One thing I've always been curious about, why is it 450? Why not 500? (or why not 400 for that matter...). I doubt we'll ever get an answer for sure, maybe it's just because it's equivalent to running expert 5 times (with daily bonus).

Sometimes you're like 5-50 short of buying a piece so you have to wait until next week. Probably that,