Save your money.

If I may offer a proven suggestion that has worked on even the most airsick amongst us: just take your thumb and fingers on one hand and apply pressure on the other wrist, palm side up. Make sure the thumb temporarily restricts the flow of blood by pressing your thumb on the flat part of your wrist below your hand. Hold it there until you feel the airsickness begin to dissipate, which should only be for a few minutes. Some people will also close their eyes while doing this to lessen the effect of motion. Others will "switch" hands and wrists after a few minutes to balance the effect. Repeat this procedure as often as deemed necessary.

In a few minutes (depending on how airsick you are), you will feel as good as new. A cold drink (preferably carbonated) afterwards will really help. No medication is necessary; in fact, some people sometimes get even sicker after taking medication.

Also, it is best to do this procedure when you feel there is a possibility of the onslaught of airsickness, rather than once the airsickness overtakes you. Prevention is the best choice here.

And yes, for those of you who guessed, this is basically how the wrist band that reduces or prevents airsickness works.