Ha! For $150 I'll eat valonia too.
Well, Ok maybe not.
FWIW, I have two fish who seem to do a bang-up job at it,
Siganus virgatus rabbitfish in one tank, and
Zebrasoma desjardini Red Sea Sailfin tang in another and they go to town on the stuff.
I never had any luck with emerald crabs, I went through a dozen of them and they never did a thing to valonia. Apparently you have to keep getting more of them until you find one that will and then you're set, but finding the few that will help is a bit annoying. I actually took a tank down because the valonia was so bad, this was before I discovered my sailfin devoured the stuff. When I took that tank down, I moved all my snails (which had become 2" roving colonies of valonia) into the tank with the tang, and within hours they were clean snails once more.
Good luck with the search! Having a bad case of valonia can get to you (heck like I said I gave up on a tank because of it .. this was before I had the rabbit).