I second
@ctinct . If your prize includes transportation, make sure you do the same once tickets are booked. Go to the airline and price out the exact flight your booked on and screenshot/print to PDF. (Or train, rental car, whatever) Do that for every part of the package. Whatever value they have listed in the contest T&C is what they'll report for taxes. But you only need to pay tax on the fair market value received. Sometimes that's close, sometimes it's not. Especially with something like Disney with all the dynamic pricing they have. You don't want to be going in low season but pay tax on peak pricing.
Also be sure to look up any state or local taxes in addition to the feds. And track what type of contest it is, sometimes that makes a difference in whether it's taxable to state/local or what rate is taxed at.
it's not a scam. I hope you enjoy!