I got a bit bored and decided to tally up what a "bare bones" DLR trip would look like from the east coast for a long weekend.
Test case: August 7-10, 2020 (3 nights) for 3 adults
JFK - LAX R/T airfare = $891 ($297pp), American Airlines
Rental car = $278, Alamo (via Costco)
Hotel = $623, Tropicana Inn and Suites (Harbor Blvd across from esplanade)
Park tickets = $1185, 4-day park hopper
Total fixed costs = $2977 (not incl. gas, parking, meals, and incidentals)
Of which, 40% is the cost of attendance. If you sub out Disney altogether, and do 2 days at Universal Studios ($169pp), 1 day at Knott's Berry Farm ($55/pp), and 1 day doing the Warner Brothers Studio Tour ($79/pp). = $909 for 3 adults.
So technically, really, the "Disney premium" here is +$276, or $92/pp.
I get that I will spend a riverboat full money at Disneyland, way more than any of those other locations, but that's controllable. You can still pack a lunch going to DL (I have embarrassing parent stories about that).
IMO, +$92/pp is worth the Disney premium over comparable attractions.