Di Gi Charat The BEST, Japanese version - What's it worth?

I've gotten hold of a copy of "Di Gi Charat The BEST" soundtrack CD recently. It's still in the original shrink-wrap and everything, and all the text is in Japanese. A bit of shopping around has revealed this important fact: This version is NOT available in U.S. retail, such as Ebay. Considering the collectable value of this for a die-hard, "Di Gi Charat is my LIFE" type fan... what would be a fair asking price for starting bids? Should I sell it online, or is it just not worth it, and I should pop the seal and give it a listen?