Been on the Pearl and will be back on Pearl May 20th, 2007.
As far as drinking and prices. It's a cruise line and a major source of revenue on a cruise ship are the drinks, both cocktails and beer, and especially wine. As Jude stated, there are specials, but be prepared to pay premium prices, no different than a US pro Baseball game, NFL Football game etc.
Best value is off ship at local bars. Suggest that you get off ship and party it up. Otherwise just be prepared to pay a little extra for the drinks and beer. It's only money and if your taking a cruise, you work for a living, so enjoy the fruits of your labor. You can always work and make more money. Don't skimp for a couple of bucks, just enjoy the cruise. The extras that you spend are to be expected. Try the specials like martini clinic's, a great value. Margarita clinics, another great value, and of course wine tasting, another great value. So the end result, there are specials and just enjoy, don't won't about an extra $100 bucks. It's immaterial considering you will probably make a million or two in a lifetime.
Don't buy the souvenir cocktails with the take home plastic glass, it's a major ripoff. Buy wine by the bottle, not the glass. Buy beer by the can or bottle not the glass, unless pints are offered in a bar like Maltings.
Can't wait to get back on the Pearl and have lots of fun at another martini clinic. They are a blast, and you always get blasted.