So I was working on getting an cooldown reduction rune page today and I found that if you click get runes, you can get one batch of runes regardless of if you have over 90 or not, then exit the get rune page, click it again, and get more runes. It's repeatable endlessly, at least as far as I can tell.

I found that out too. But since the grab bag implementation is only available for beta testing, its pretty much non-issue if it's going to be dropped in a few months.

This is a known bug. Beware if you use it though as Zileas made a post saying it might make your account error and be unplayable to the point where they can't fix it.

800 Tier 3 Runes FTW! =D
Its nice having a page devoted to one thing, the runes actually MAKE A DIFFERENCE instead of doing nothing - although i suppose when the game is released to the public, this sort of thing will indeed be possible ( to stack same type runes) due to buying them and such =)