mammalammadevil found me a very cool Professional Art Marker Case. The site only lists them going up to 72 markers, which means I'd have to get two. However, their paper catalog apparently has one that holds 144, so I'm investigating that. It definitely looks promising!
The auction ends in two hours, and the price is still at $85. Unless there's an unexpected flurry of sniping, I think that's as high as she's gonna go. Not quite as high as I'd hoped, but still not bad. Maybe the commission will go higher.