The recently released Black Ops with the extra First Strike map pack included is listed at Amazon for $49.99 for 360 and PS3. I didn't see this anywhere but I figure it is a good price with the DLC included. Apologies in advance if this is common knowledge.
360:
http://www.amazon.com/Call-Duty-Black-Ops-Xbox-360/dp/B00519C7CE/ref=sr_1_12?ie=UTF8&qid=1312228191&sr=8-12
PS3:
http://www.amazon.com/Call-Duty-Black-Ops-Playstation-3/dp/B00519C7JC/ref=sr_1_9?s=videogames&ie=UTF8&qid=1312228517&sr=1-9
360:
http://www.amazon.com/Call-Duty-Black-Ops-Xbox-360/dp/B00519C7CE/ref=sr_1_12?ie=UTF8&qid=1312228191&sr=8-12
PS3:
http://www.amazon.com/Call-Duty-Black-Ops-Playstation-3/dp/B00519C7JC/ref=sr_1_9?s=videogames&ie=UTF8&qid=1312228517&sr=1-9