I'm working on rewriting this prompt to include as many tried and tested NVME options for the Steam Deck. They're sorted from best to worst value. Again, these have all been confirmed and are a direct replacement for the Steam Deck.
2TB Models:
Micron 2400 2TB Drive ($150-$300)
ShopBLT is a long standing distributor of electronics, they're not a retailer and that's why you probably haven't heard of them, but they have a wait-list due to their distributor pricing on NVME drives. You get a full warranty, but may have to wait up to a month or more to get your order.
It's also available from iFixIt for $300. (Please don't buy it from here 😂.
The 2TB Micron was also listed on NewEgg for $160 but sold out immediately and hasn't been restocked in weeks. Some people who purchased it while in stock also had their orders cancelled.
WD SN740 2TB ($140 - $300) readily available on AliExpress from several different vendors. There's a TON of confirmed purchases on the subreddit, but I will not link to an AliExpress vendor because it's a risk you have to take for yourself. Be mindful that people have received fake, or dead drives or nothing at all from time to time. You also have to be aware that if you're in the US, you won't have a warranty from Western Digital as they are OEM drives for a different region.
It is also available from frameworks for $300 (please don't buy it from here 😂.
1TB Models:
Micron 2400 1TB ($82-$160) again, distributor pricing with ShopBLT, but it's backordered. iFixIt also has this option available in their drop-down.
Samsung PM991a ($85-$100) is another option for the steam deck and will work as a direct replacement, they are available on NewEgg. You can also find them on eBay in both new and used conditions. Your experience with ebay will vary. This is also a Gen 3 drive, but is higher on the list than the WD SN530 that's listed below because it has higher read and write speeds.
1TB Corsair MP600 ($109) the new kid on the block. It release at a great price and should be available for purchase. The release of this drive made Microcenter drop the price of their older TN346 drive to match it.
Inland TN346 1TB ($109-$130) if you're lucky enough to live near a Microcenter you can swing by and pick one of these up for $109 when on sale. It's also available on Amazon, but I believe it's more expensive because shipping etc...
Inland TN446 1TB ($130-$160) the second newest drive to be released right before the Corsair, it debuted at $160 but dropped to $130 immediately after the Corsair was released. Its faster and newer than the TN346 but due to the Steam Decks limitations, they should both run about the same in the Steam Deck.
WD SN530 1TB ($109-$115) this drive is available on NewEgg but it's an older Gen 3 drive. It will still work in the steam deck at its peak performance, but it's still slower and older technology. I believe it is also discounted which may make warranty claims a bit harder.
1TB Sabrent Rocket ($160) The Sabrent Rocket sells for $160 on Amazon, it's the bottom of the barrel in terms of value, and there have been a lot of posts of failed drives on the subreddit and on the Facebook groups. If you pay $160 for this drive, in my opinion, you're paying for marketing, plain and simple. There are similar drives for a better price....
The Micron, Sabrent Rocket, WD SN740, Corsair MP600 and both Inland TN446 and TN436 will perform nearly the same in the SteamDeck due to the PCI-e gen inside the deck.
Micro SDs:
Regarding Micro SDs, there are 2 main cards that this subreddit will recommend.
Samsung 512GB Evo Select (this doesn't have a 1TB option)
Or
SanDisk 512GB Extreme (this DOES have a 1TB option, so buy what's in your budget)
Keep in mind that the Evo Plus and Evo Select are the same cards just rebranded for Amazon. I believe Evo Plus is what Amazon has the rights to, but they're the same.
An honorable mention is the Silicone Power 1TB MicroSD which is a value buy with a few successful purchases and reports both here and on the Facebook group. Haven't seen any issues pop up yet.
This is better