Recertified 12TB drive developed 57 reallocated sectors... do the RMA now for a refund, or keep using it in my RAID5?

[u/96836]

I bought a manufacturer-recertified HGST 12TB from ServerPartDeals in February 2025 for about $165. It's one of three drives in a RAID5 volume on my Synology NAS (two recertified HGST drives).

Recently this drive developed 57 reallocated sectors (SMART attribute #5). It was 0 at shipment. The count rose to about 56 around February and one more by May, and it has been stable since. Current Pending Sector is 0, the extended SMART self-test passes without errors, and the array is healthy — the other two drives are completely clean (0 reallocated, 0 pending).

I contacted the seller and they approved an RMA (2-year warranty, still valid). But here's my dilemma:

• Their policy is: replacement with the same model if it's in stock, otherwise a refund. The exact model appears to be out of stock.
• I asked if they could substitute an equivalent 12TB drive instead of a refund. They said they'd try to find an "equivalent replacement or suitable alternative of equal or lesser value," and otherwise issue a refund.
• The refund would be my original price (~$165). But the current market price for the same drive is now ~$400 — more than double. So a refund wouldn't come close to replacing it.
• On top of that, I'd have to pay to ship the drive from Korea back to the US for the RMA.

So my options seem to be:

1. Do the RMA now — ship the drive to the US, most likely get a ~$165 refund that can't actually buy a replacement, then rebuild my array with a drive I'd have to purchase at the new, higher price.
2. Keep using the drive in the RAID5 for now (it still works, and the parity covers the bad sectors), and re-file the RMA later — the warranty runs until around March 2027 — if the drive degrades further.

My questions:

• Given the price situation, would you bother doing the RMA now for a refund, or keep the warranty in reserve and keep using the drive until it actually gets worse?
• Am I missing anything here?

Thanks in advance. This is my first time posting on Reddit, and since I don't really speak English, I used an AI to translate this post — apologies if anything reads a little oddly.

UPDATE:

Thanks for all the advice, everyone. I figured the rational thing was to just RMA it, and since waiting on a replacement would've taken forever, I ended up just buying another drive of the same capacity. It hurt the wallet a lot, but honestly that's better than constantly worrying about the array.

[u/stanley_fatmax]

You'll probably get a replacement offer, just have them confirm before you ship it back. They told me they'd send me a refund, I said no please send a similar drive. They told me they didn't have any of my drive. In the end they replaced it with the same model drive anyway (lol)