You are supposed to pay taxes on a prize for the year you "receive" it, not when you win it. As good as a CPA may be, most do not have much or any experience in handling sweepstakes winnings.
Plus, you only pay taxes on what the trip actually costs not on an approximate retail value (ARV). How, can you possibly pay taxes on something that hasn't been received, hasn't even been paid for, and not yet know the actual costs of. That would be ludacrous.
I would also suggest you do not take tax advice from people such as H&R Block who are known to royally mess up people's tax returns.
I suggest you contact the sponsor and request that they reissue the 1099 for the year you actually receive the trip and "after" they know what the actual costs of the trip will be.
If the sponsor decides to be difficult about this, contact the IRS and explain the situation. They have procedures to try and get the sponsor to issue a 1099 on the actual costs/value.
Usually, these mistakes occur through the ignorance of the sponsor's accounting department.
We've encountered similar problems on several occasions before, addressed the problem with the sponsor contact, and had the 1099 changed with no problems.