For reference, the 1TB Steamdeck OLED at Gamesmen is $450 AUD more than what Valve will be selling it at. Unless I’m mistaken, Gamesmen are the only retailer selling the Steamdeck online that isn’t a marketplace (such as Big W), so Gamesmen is probably the best place to but at the moment since they will be forced to take on any warranty claims unlike resellers on marketplaces which may able to just dodge that by closing up shop.
I’m guessing Steam decided against being able to leave your games to somebody else when you die because of how most EULAs I’ve read work: they are often non-transferrable licence and so in most cases the store has no choice in the matter. Now GOG are willing to say they will do what they can given this limitation, but I can see why Steam wouldn’t: it’s a whole lot of work for realistically not much benefit. It’s probably easier for Valve to gift the same games over to the new person.