Although the main $5 offer has ended it's being offered by impulse for $5 if you buy the expansion warband. I haven't played warband but mount and blade has proved one of the best purchases I've made in terms of value of money. So long as you're not put off by the lack of a story (i.e. you make your own story rather than having a specific path laid out for you) it'll prove a very entertaining game. The combat system in it is IMO amazing, and it's open to lots of different styles of play. The mixture of being able to command an army while also taking part in the battle yourself also works particularly well.

If I was to rate it I'd probably give it 8.5/10 - it's rough around the edges, but the core experience is well worth it. It was a bargain at $5 and still good value at it's normal price.