Perhaps raid roulette would work best under the criteria that:

You have cleared all raids (not savage)
You have an item level of 250
You are level 60

Rewards 250 Lore - 150 Scripture.

Of course, this would auto lock similar to mentor roulette when more content is released and when new tomes are changed the reward would change too.

It makes sense to me to exclude savage content but have 24man/8 man raids from ARR/HW but also having the need to make the reward attractive due to difficulty to have a high tome output, otherwise it'd be pointless to run.