Yes, we track our costs, but to be truthful, much of our vacation expenses are paid well before we leave. We like spreading out the cost so that as much of the vacation is paid for before we go.
For our Jan/Feb 2011 trip, we have already purchased our airfare, put down a deposit on our condo, and have bought the Disney tickets for DH & DD. I will purchase park ticket in the next month or two (depending on what our Canadian dollar does).
The condo will be paid in full 6 weeks before we go. So the only expenses we will incur in Orlando are:
Car rental (we always keep trying trying trying for better rates, right up to the last minute).
Food for the week (but we would have to buy food at home too, so some of that money comes from our regular household budget).
Souvenir (we buy one item, and ONE ONLY, for DD on each trip).
Now, here's the thing... DH and I both actually wait to get to Orlando buy ourselves new clothes - we would never buy them before! The prices at the outlets and the low low taxes you Americans pay... it's heaven!

But we don't include the clothes purchases as vacation costs - more like an incidental savings

.
Here's our own breakdown:
Airfare: $580 for 3, BUF to MCO return
Car: Estimating $300, but hoping for much much lower.
Disney Tickets: approximately $650 for 3 people, 6 day tickets (
Undercover Tourist)
Food: $300 for 8 days, includes some eating out and some cooking at condo
Parking: $75 + $50 for airport parking
Pet Sitting: $100 gift card for friend
Souvenir for DD: up to $100 for one item.
Total: $2,100 or thereabouts.
Last year we spent $2,100 - but again, that doesn't include the clothes purchased at Victoria's Secret, Banana Republic, Gap, Rockport....