Elgin is $15k for k-4, but Einstein is $11k which is a bit less. Still, a lot of money.
D54 might be worth looking into, although I'm not sure my husband would agree with moving in the hope that she makes it for 2013-14. He works in Lake Forest so it's quite a trek, at least with CPS he could commute fairly easily.
How have you found them so far outside of the magnet? My younger one is only coming up to 2, but he's showing a lot of the same signs she did already. If I'm going to have two gifted kids to educate it will definitely have to be public!