Wow, that's a pretty good deal! Here's what I read about the offer :
The Costco
Disneyland ticket offer can save up to $150 per person on the purchase of a 3-day park hopper ticket with
Lightning Lane Multi Pass. The new offer is valid for admission May 20 through December 19, 2025.
This ticket costs $449.99 for all ages and includes Lightning Lane Multi Pass and Park Hopper. You would pay $601 for a standard multi-day ticket with the same perks. It's cheaper than the Disneyland Anniversary 3-Day Park Hopper Ticket, which runs $546 with Lightning Lane Multi Pass.
The ticket offer also includes a $30 Disney Dining Gift Card.
Things to know: all three admission dates must be used within 13 days of first use. In other words, you would need to use all 3 days within a 13-day time frame.