There's a fair amount of availability currently in Epcot. I agree MK is in need of more dining capacity, but I'd also say Contemporary and Poly are quite close to MK. It sounds a little whiny to say that hopping on the monorail is too hard.
now, taking a boat from MK to WL though can eat up close to an hour, so IMO, losing an hour of park time could easily = more than $50 for a family. Mid-March, a 4-day base ticket costs almost $130/day. If a family plans to be in MK for 11 hours (9am-8pm), that's $11.72 per person per hour. For a family of 5, losing an hour of park time costs about $60. ($58.60)
Then again, if they are choosing a table service meal during park hours, they are losing over an hour, even if they eat in the park. Not only are they paying about $30 more per adult (over QS), but the meal also costs extra park time (over choosing to eat a QS meal, or just snacking).
but most people don't really think about park touring that way...