Molded plugs are no more protective than inexpensive foam plugs. Their one advantage, other than providing someone else with your money, is that if they are properly made they are easy to insert properly every time.
Foam plugs come in standard and small sizes so if you have a problem getting them to seat you can get the ones for folks with small ear canals.
Almost everyone puts foam plugs in improperly. You have to compress them much more than you think you need to. They should be rolled between your palms until they are about the diameter of a drafting pencil lead. Insert them into the ear until the tip reaches the bend in the ear canal then hold them for a few seconds until the expand.
Not only are they cheap and effective, but they can be washed a few times and reused.