Buy.com has it for $43.99, not sure if that is a great deal or not but, from what I saw online it seems to be the cheapest price for the limited edition.
http://www.buy.com/prod/Halo-Reach-Limited-Collector-s-Edition/q/loc/108/216082529.html
http://www.buy.com/prod/Halo-Reach-Limited-Collector-s-Edition/q/loc/108/216082529.html