So I thought I would do some comparisons. The Expedia deal has an adult 5 day parkhopper (3 day ticket with 2 days free) for $318.46. The
undercover tourist price with the mousesavers link is $317.44. You can get cashback (2.5%) by purchasing from Expedia through ebates or shop at home which would technically make it cheaper than the undercover tourist price but the savings would be about $7 I think. That makes Expedia the better deal but I don't have any experience with purchasing ticket from Expedia and whether that is more of a hassle or not.