Check Groupons, Living Social and change your city to the new area. Otherwise, go to the local Costco or Sam's club. They will have dining as well as amusement parks. If you know a student or someone who works at a school, the state University system offers very good discounts for their staff/faculty/students. Look up a local university and then look at what's usually called the Box Office.
By the way, unless your kids are above 36" (48" is better) I'd forgo Legoland unless you just want to go because it's the only one and you like just looking at cool Lego statues. Otherwise, I found it not worth the cost. Sea World is fun though. If you are looking for rides with small children I'd go to Knotts Berry Farm. It's smaller but you kids will enjoy Snoopy alot more and the rides are fun though not as dangerous as Magic Mountain. Plus, you don't get to go to Knotts anywhere else in the country. It's has a historical aspect to it as well if you want to teach kids about California and US history. A big plus is that it's much cheaper to go.
Another cheap thing to do which gets overlooked is seeing a video taping. Tickets are free, you just have to stand in line a few hours before the show to be sure to get in. There are various tv tapings so you can search "tv taping (name of show)" and you'll be linked to who handles tickets. Also hit the Getty Museum in Los Angeles and Griffith's Observatory (You'll see the HOLLYWOOD sign) but it's a cool observatory in and of itself.
Feel free to message me and I'll see if for the time you come out here there are any tips or coupons I run into.