Im the money guy. :)
You are only factoring in the "hotel". Think about travel time (i'm in the IT business.... Time IS money,) and the VALUE in using the Disney transportation system. Plus, on property, you get the Disney Magic at all times. Remember, on Disney property you get CAST members, not just simple employees of gigantic chain hotels who could care less. I mean it when I say it, cast members CARE that you have that 'pixie dust' experience.
Wait till Tanya tells you about the simple, yet MAGIC moment "Joe", a concierge from Bay Lake Tower gave to Hannah. It brought a tear to my eye. (Yes, I, Puckstop31 the evil, CRIED many times on this trip. Sometimes for my daughter <positive cries>, sometimes for my dad.... Another story.....)
Yes, in pure $$$ terms, staying at Disney properties (especially in California. Ugh. Crazy points/night for Disneyland stays) is expensive. But, IMO, its worth it. Period. Disney delivers on the value you expect for what you pay. Also, being DVC cuts the retail costs you see on the main website at least in half.
Like I always say.... Do your own homework. :) There is usually a better way than that mainstream thought.