Medicare copays on my advantage plan are very reasonable or in some cases free until I enter the donut hole.
When the retail value/cost of my prescriptions goes above $4,430, I pay 25% of the suggested retail price and Medicare pays the balance.
I also have a state program called EPIC that helps while in the donut hole, after I meet a fairly substantial deductible based on my previous year's income. That usually kicks in around the end of October and helps for the remainder of the year.
Medicare combined with a zero premium advantage plan is still a great bargain compared to what I was paying for health insurance.