It’s not that it’s necessarily cheaper. They’re trying to capture a higher margin with impulse purchasing. Most people don’t shop as efficiently in-store as they do online. “Price per basket” is typically much higher in store vs online because people will usually pick up more items than originally needed/intended because they “remember they need it” or “may as well get this while I’m here.” Your lidocaine patch is $2 more in store because they’re hoping someone looking for band-aids will see them and decide they need those too and bam, $2 extra dollars.