Well, the trip varies each year, as does the cost.
My most expensive trip, per capita, has been to stay at the Disneyland Resort at DLC. Way overpriced, and once you add in spending money and flights, it cost more than a Disney Cruise. If I go back to DLC, I will be staying off property. It's just not worth it.
In 2010 it was me and the kid, we stayed at CBR with the Deluxe Dining, and it was around 5k when all was said and done (shopping, park costs, etc...) for 14 days.
In 2011, we went as a group of 1 adult 1 child for 1 week (me and the kid) and then 2 more adults (1 10 year old uncle and my kid's mom) for the last week. That trip cost around 8k, including shopping, etc.
In 2012, we ran way below my shopping budget, and the whole trip, with 3 days at a Universal resort for 1 kid 1 adult, and 10 days at Disney cost around 5k.
This year we are doing a split trip, and it's expensive, and will be the last year I do this for a while. For 1 kid, 1 adult, we are doing 1 night at Contemporary, which with Deluxe Dining (and yes, I crunched the numbers, we'll use the credits and come out about 200 above the cost), costs about 1k. Then we are doing 7 days on the Disney Fantasy, at a nice stateroom, which costs about 4700 total for that week, plus another 1k or so in port activites, which I haven't decided on yet, so I can't nail down that cost.
Then we are doing 10 days at POFQ, which is another 4k, with Deluxe Dining Plan. The last leg of the trip I'm still iffy on, not sure if we'll be too tired, if we'd rather do something else...
But there's the costs for this year. Add in a few grand of spending money, and it is way to much, but I'm sure we'll enjoy it.
I felt I should clarify, I don't make that much. I live on a miser's budget to be able to afford these sorts of events. I eat on about 0 a month, for example.