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

[SendohJin]

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).

it's not 500 because they do not want you to be able to buy a small left side piece per week. it's not 400 because they want you to be able to get a large left side piece after 2 weeks. the tomestone cap and the cost of the items are closely related so that players can only get the amount of gear per week that they want us to get.

[MicahZerrshia]

It also creates an artificial sense of "newness". If we are just constantly grinding out the same tome it would become more stale on a psychological level. By simply renaming the tomes they are giving us a "new" reward to work toward. We me know on the surface that it's just another tome but on an unconscious level we are seeking a new and better reward. It's a little jedi mind trick that games use to keep the same ol same ol seem fresh.