A popular chain shabu-shabu restaurant, near Disney store.
All-you-can-eat and all-you-can-drink course is from ¥5,000.
Another popular chain restaurant, same group as Gyukaku. Pork and vegetable all-you-can-eat shabu shabu is from around ¥3,000. Their all-you-can-eat menu is various, includes tsukune (chicken meat ball) and various side dishes, too.
This is the cheapest I could find, all-you-can-eat and all-you-can-drink is around ¥3,000. I have never been here so I don't know if they are good or not.