You're referring to a replacement ice maker unit for the freezer section of your refrigerator? Find the correct item by part number, search for the best price. I'd do some searches for you but you didn't state either the brand & model number of your refrigerator or the part number of the ice maker.

FiltersFast, WaterFiltersExperts, and Amazon carry such items but are not specifically appliance parts sources.

Supco is an after-market parts manufacturer, not OEM (original equipment manufacturer) ... but may be a viable choice, and in some cases the only choice if the manufacturer has discontinued parts for an older model appliance.

Be aware also that there may be two ice maker version offered -- 1) a kit to add an ice maker to a refrigerator that doesn't already have one (includes a water valve and other parts); and 2) just the ice maker mechanism for replacement on a refrigerator that already has one.

Among many other sources ...
SearsPartsDirect.com
PartsTap.com
AppliancePartsPros.com
RepairClinic.com
ApplianceZone.com
PartsDr.com

When I posted that, I wasn't sure what the part number was. There were a lot of numbers inside the front cover of the old one, and two of the numbers matched ice makers that said they were compatible with Whirlpool. Then we pulled out the freezer and on the back it says to use ice maker kit ECKMF94 or IMKIT94. So I just found the first one at a couple of places too, and one reviewer on Amazon said they bought it at Lowes. That would be great for me, because then I could see it and know it was new.

ECKMF94 and IMKIT94 (substituted now to P/N 8560) are different numbers for the same item, both are the full installation kit ... includes water valve and tubing, fill spout that mounts in the freezer rear wall, ice storage tray, mounting hardware.

Interestingly, a full kit can be cheaper at some sources than just a replacement ice maker module.