$4 will get you remakes of the multiplayer maps Hang 'Em High and Derelict.
Microsoft Games and Bungie Studios have confirmed the upcoming release of two new downloadable maps for Halo 2: Tombstone and Desolation. The two maps will be available to Xbox and Xbox 360 Halo 2 players from April 17 for $4 for the pair.
Tombstone is a re-imagination of Halo classic map Hang 'Em High, will all-new graphics, features and hidden surprises. Desolation is a remake of the original Derelict map, with new graphics and effects, and improved balancing for play in Halo 2.
For those thinking that the maps were intended only for release on Xbox 360, you're correct, but Bungie decided they'd release the maps for both consoles
"It was originally scheduled to be a 360 only game, but it just wasn't going to work out," explained Bungie's Frank O'Connor. "Number one, there are a lot of Xbox players out there who can't afford a 360, or are waiting for a birthday or holiday gift - so they wouldn't be able to play. Worse still, we'd have to split the matchmaking playlists differently and that wouldn't have been fair either. So in the interests of fairness and an easy life, it's on Xbox and Xbox 360."
Because the maps are for an Xbox title, you'll also need to use real money and not Microsoft Points to make the purchase. It's also worth noting that the content is non-transferable meaning if you buy it for Xbox then upgrade to an Xbox 360 you'll have to buy the content again.
Expect the new maps to be integrated into the Halo 2 Matchmaking shortly after their April 17 release.