Whats affordable to one person isn't to another. I'm paying $4200 for 9 nights at a Value for 4 adults, 10 day park hoppers and regular dining plan. I'd love to see any offsite deal touch that (With equivalent food since DDP isn't available off-site). Offsite may also require expense of airport transfer or rental car and parking fees.
Just because it sounds like a challenge, here's my similar offsite vacation:
$890.00 1 week at Sheraton Vistana Resort - 2BR townhome villa (more like a 3BR with the sleeping loft)
$360.00 2 additional nights at Vistana booked through Sheraton (with common discount code)
$2,022.28 4*10 day hoppers (tax and shipping incl,
UT)
$600.00 food (based on my records for last 6 trips, I've never spent over C$500 for our family of 4 for a week. I think US$600 would be doable - combo of onsite, offsite, breakfast is usually in the villa)
$450.00 rental (although we actually drive so I wouldn't pay this, but I should be able to get a 9 day for this price with discount code). Driving down saves me about $2,500 over flying 4 from Canada.
$180.00 parking at the parks.
$4,502.28 Total, about $300 more than your onsite, but close. It's lower than your onsite without the rental car.
That's actually quite a bit more than what my one week vacations actually cost, but I'm being pretty liberal in my estimates.
Again, not trying to convince anyone to stay offsite, I think the Disney bubble lovers need to do their thing. Just adding more "math" to the conversation.