Only Grim Fandango comes ahead of it in my book, and yes, I've played all the Lucasarts and Sierra adventures. It's also the only game to make me cry, since by the end you're so attached to the characters that you don't want to let them go. This game would be worth it at $50 and if you haven't played this game, you haven't experienced interactive storytelling.
World of Xeen alone is worth the 10 bucks. Might and Magic 6 is worth it. The others combined are worth it. So you're getting hours and hours of fun, colorful gameplay at a bargain. Beyond simply hack and slash, these games created a world that was as much fun to wander through as to level up in.