According to Major Nelson, 3 arcade games are permanently slashed down in price.
If you get on Xbox Live, you’ll find that three games have had their prices reduced by 400 points each. This isn’t a sale, this is a permanent reduction.
Crank up those trials and try them out. Braid is a very good game especially for that price. Cloning Clyde is a funny platformer that is fun and some people may enjoy it especially for that price.