With the sorts of metal and rock shows I go to, it seems like the 12-15db that flat response earplugs reduce isn't enough. My ears still ring with foams that do 33db, even with the highs being muddy. Are there any really expensive ones that have a flat response to at least the 20db level?
With foam, it's like being at a rock show underwater. With musician's earplugs, it's like being at a rock show at a reasonable volume. Spend the $20.