AresTravel.com sells them for cheaper than at the gate or at the DL website.
Sometimes, there are special discounts for So. Cal. residents--you just have to keep your eyes and ears open (and keep checking on websites like this!)
Last, for $134 each, you can buy a So Cal Select Annual Pass. That may seem expensive, but if you're going more than one day a year, it's a real deal! There are quite a few black-out days with it, but you can't beat the price.
Also, if you're college students, many universities/colleges in Southern California offer one-day, one-park
Disneyland and DCA tickets at major discounts; check with your student union and see if that's available. There are also discounts at military bases (if you're in the military) and at some large corporations and workplaces. Also, several credit unions offer discounted tickets. Check with everything you're a member of, in other words!!!