A regular plastic (double) DVD case for the $65 pledge would indeed be a little disappointing. They could consider a similar case to what I describe below.
I think that WoW has done this right with their standard editions. It's a regular DVD case inside a same size embossed cardboard box with a flip out front. It has a very premium feel for it's price point ($35) but also has the standard plastic case for those who want the convenience of that.
Edit. Also, I would like to see a big high quality box for the CE (since I'm paying mainly for the box in it), similar to what Blizzard releases have.