I agree that getting a rental and drive yourself to Disneyland starting out dawn is best. There is really no point staying at Anaheim.
For Santa Monica hotels at that pricing we have stayed at Inn at Marina del Rey, just value for money. Great breakfast to boot. Last I checked the price was $129 a night. http://hotel.roomratesdirect.com/Hotel/Inn_at_Marina_del_Rey.htm 
It's located at the town center,free wifi was great and parking never was a problem.