I often find myself asking the same question. DH and I are attorneys with decent salaries who live frugally, but there is no way we could afford to go "all out" on a Disney vacation. Yet there are many people on this board who go to WDW multiple times per year, and their trip plans always include deluxe accommodations, deluxe dining plans, lots of extra paid experiences, and a "money is no object" attitude. I wonder how they do it, too, but clearly they have a much higher income (or a higher debt tolerance) or just like to allocate their spending differently, than many of the rest of us.
While their carefree mention of their spending, ("Yes, we thought about saving 85% of our room costs by downgrading to a Mod, but I just can't LIVE without my $1,000 per night club level room at the Poly, you know!") may give the impression that just about everyone here is lounging around in silk smoking jackets with a teacup poodle in one hand and a diamond-encrusted iPhone in the other, let me reassure you that this is not the case! Most of us here are looking to save where we can, and consider even a bare-bones a Disney vacation a "splurge" all by itself.
We do a middle-of-the-road approach. In the past, we generally stayed in moderate resorts, in standard rooms, during times when there was a discount offer (usually around 20%) in place. We only get the dining plan if it's going to save us money, depending on where we're eating. There are four of us: 2 adults, 2 children, and we go for 6-7 days, 5-6 nights, and go during an average or lower pricing season. Total vacation cost (tickets, food and room) without airfare is $3,000 or less. We plan to go about once every 18 months.