We stayed at the Travelodge on Sierra Highway, about 10 minutes from SFMM.  King size bed, little kitchenette(microwave, kitchen sink, fridge), and  a pool for $50 a night.  Can't beat it.  From Magic Mountain, like I said, its 10 minutes away.  If you're interested email me at 
CalvinHobbes21@hotmail.com and I'll find the address and what not for you.