What is the average cost for a cruise from Baltimore, MD to Bermuda for 2 seniors?

In this economy, I am praying to find a great deal on a 5 day cruise for my parents ages 80 and 65. I would like to send them around their B-day which would be Oct 29 & 30 of this year because their B-days are to back-to-back, I thought this would be a great surprise because they have never been on a curise before.