Well, the actual soundtrack CD runs about $5, while what you've found is a bit different. It certainly FEELS a bit bootleg, with a maxed out running time of 78 minutes. Digging around online, it looks like it was listed on Amazon for a short time and one of the buyers was fairly certain that it was a bootleg. Based on a prior release of the score also being denoted as a bootleg (
Mulan: Deluxe Edition by Jerry Goldsmith - RYM/Sonemic) I'd say you've hit it on the head.
That said, even as bootlegs go, this one seems pretty rare. It is likely priced fairly appropriately.