@Jo117 It just really depends on what options you go for. A biggy is if through your employer you can get a supplemental or gap plan. Once we switched to Medicare everything ended up cheaper but that is because of a supplemental plan through my husbands past work place.
Advantage plans can be cheaper but limit your options in doctors and possibly what drugs/insulin you can get. Regular Medicare with a supplemental gives you more choices, but the supplemental/gap can be an added cost. Medicare actually covers a pretty good range, but you need part A, B and D. Part D is pharmacy.
It feels very confusing at first.
Here is an older thread discussion on Medicare. Keep in mind that each year plans can change.