A lot of that is just good old fashioned marketing.

Here's the list of ingredients for Excedrin Migraine:

Active Ingredients: Acetaminophen - 250 mg (Pain reliever), Aspirin (NSAID) - 250 mg (Pain reliever), Caffeine - 65 mg (Pain reliever aid) Inactive Ingredients: benzoic acid, carnauba wax, FD&C blue #1, hydroxypropylcellulose, hypromellose, light mineral oil, microcrystalline cellulose, polysorbate 20, povidone, propylene glycol, simethicone emulsion, sorbitan monolaurate, stearic acid, titanium dioxide

This is the list of symptoms that Excedrin Migraine claims to treat:

- migraines

And now here's the ingredients for Excedrin Extra Strength:

Active Ingredients: Acetaminophen - 250 mg, Aspirin (NSAID) - 250 mg, Caffeine - 65 mg Inactive Ingredients: benzoic acid, carnauba wax, FD&C blue #1, hydroxypropylcellulose, hypromellose, light mineral oil, microcrystalline cellulose, polysorbate 20, povidone, propylene glycol, simethicone emulsion, sorbitan monolaurate, stearic acid, titanium dioxide

This is the list of symptoms that Excedrin Extra Strength claims to treat:

- headache - toothache - a cold - arthritis - premenstrual & menstraul cramps - muscular aches

And while SOME places have normalized the prices between the two, they can be often found on shelves at two different price points.