Check prices on online (e.g., Amazon.com, or other outfits you trust). The important thing is that the filter you get needs to be the right one (shape, size, model #; whatever) for the exact fridge you have, so that it fits and works and stuff. My filter (for a Samsung fridge) just screws in like a car's oil filter, only easier.

Its certainly worth checking online retailers for a better deal than you'll get at the local stores or through KA. But look for the filter made for the fridge you have, most likely by KA.

I've ordered from these websites in the past. They used to offer six-packs which gave you an even bigger discount but now they only seem to offer 2-packs. There are probably other websites as well. The ones I bought were authentic Whirlpool/KA filters. As chac_mool said, make sure you get the correct one.

http://www.filtersfast.com/

http://www.thefilterstoreonline.com/

Breezy,

Try a Google search.
I've replaced my Samsung CD/FD water filter with an aftermarket unit for almost 1/2 the price and have suffered no consequence.
My sympathies for your recent loss.

Will