Costco is selling a 512GB Lexar Portable SSD (SL100) for $124.99. That’s an odd product since the SSD really shines as an internal drive. For an external drive, I’d rather pick-up a large capacity external hard drive than a bunch of smaller capacity SSDs.
There are quite a few listings on Amazon and eBay reselling this unit for a lot more. And all they show is the cardboard placeholder from Costco.
For fast backups on location, these drives are great. Especially for travel, since you don’t have to worry about moving parts breaking. Larger drives are great for long term back up, but the read time is terrible even if they say USB 3.0. The internal drive doesn’t even come close to the usb 3.0 speed on large non SSD drives.