I actually decided to let myself of the "everything has to be equal" guilt trip last year. I have 4 kids, and realistically, the 8 year olds toys are getting more expensive, while the 1&2 year olds dont really need a lot more toys, and they have no clue how much money is spent. There is a difference between fair and equal, and I think that you could focus on that. Maybe do more family gifts as well..like this year we are getting a wii as a family, with a few small gifts for the kids too. But, if I spend more on one this year, that is ok..maybe next year a different child will have something he or she cares about that costs more..in the end, it will all balance out. Last year I was just buying the little kids stuff, just to be equal..nonsense in my opinion. Do the best you can! The kids should not be counting presents, or price amounts anyway in my opinion. Good luck!
~A.~