Would somebody be able to tell me the difference between these two coolant reservoirs from Kia?

Background: 2016 Kia Rio LX 89k miles

So, I was trying to diagnose the reason for a P0116 code that came up on my check engine. I was going through the steps of replacing the ECT sensor because I thought it was just a bad sensor, and when trying to drain my coolant, I found that my entire coolant reservoir is leaking from the sides, as I tried to flush it with water. No cracks, no holes, just leaking from the seals that hold it in place.

I'm looking at reservoirs on the Kia website for a replacement and there are some different ones they have listed for my make/model. Why is one here listed for $55 while another is listed for $82. The only difference I am seeing with the part is the part number (1W600 vs. 1W500). The 1W500 is more expensive for some reason. Does anybody know the exact reservoir I should order?

[1W600 reservoir](https://www.kia.parts/oem-parts/kia-reservoir-assembly-986101w600?c=bD0xNCZuPVNlYXJjaCBSZXN1bHRz)

[1W500 reservoir](https://www.kia.parts/oem-parts/kia-reservoir-assembly-986101w500)

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This last reservoir is the cheapest option:

[1W510 reservoir](https://www.kia.parts/oem-parts/kia-reservoir-assembly-w-shl-986201w510?c=bD0xNyZuPVNlYXJjaCBSZXN1bHRz)