I also have Ar tonelico Melody of Metafalica, taken out of its shrink wrap but never played, however it would take a fine offer to get me to part with it. It also has the OST and art book with it as well as the outer cardboard box.
Before I go I am just going to toss these words out there since you seem to like Ar tonelico; I have the art book for the first game in mint condition which I'd be willing to part with for the right price.