We tried it out, and it was lots of fun. Yes it is a bit pricey for only a few minutes, but it is more than just the dive part, they also give you lessons, and that takes a bit longer. It is also pretty tiring, so if you are new to the experience, you might only be able to do it for a few minutes without getting tired (You might even be a little sore the next day - because you use muscles you may not normally use too much.)
They also offer you a dvd of the experience. Again, it is a little pricey, but it's kind of a cool thing to have.