If you have insurance- many drug manufacturers have discounts or $0 pay options! I use Breztri and AstraZeneca offers a discount card to get it for $0!! Check out the manufacturer’s website for discounts. 😁
Breztri is a good alternative. You can also see what the individual components of Trelegy would cost as inhalers and the advantage is that you'd get to use the component that works well for you in each class. I think there are nebulized versions of all three meds available as well, so that makes it part B and not nearly as expensive.
There is reduced price assistance for discount drug costs if you have commercial (private) or ACA insurance plans (not Medicare).