Production of the New Nintendo 3DS XL ended in the summer of 2019 and new stock of the device has dried up. The only device in limited production is the New Nintendo 2DS XL, which will continue for the time being, however, if you want the 3D enabled version now is the time to buy. The same if you want new stock of the 2DS version.
The reason to buy now is that with production just having ended, we’re at the peak of functional devices in circulation. New stock is at unreasonable prices on resale sites, above the $199 original retail and sometimes even higher. Used devices are for sale at basement bargain prices, such as $89 during the GameStop holiday sale, making them at the lowest price you’ll see them – it’s only up from here.
The longer we go from when production has ended, the more devices that will be thrown away, broken, screens cracked, etc. So now is the best time to find a device that’s in functional good quality that’s used, so now is the best time to get them, especially if you want one of the collector’s editions.
Additionally, accessory production for both the 3DS and 2DS has ground to a halt. Hori no longer has many of their products in stock on Amazon and you’ll only find a few manufacturers of screen protectors and other accessories are limited.
Games are also at their lowest price you’re going to find them. Again, production of most games have stopped. So you’re going to find fewer and fewer new stock for sale in stores that’s going to be heavily discounted and used stock is likely at its peak.
While the GameBoy’s prices have remained rather low (you can get both the GB and GBA for under $100 and sometimes under $50 on eBay), they were also low tech simple machines with easy to repair parts and there is low demand for the actual consoles due to myriad of reasons, like availability of game carts and the fact that the NDS is a superior GBA console.
The New 3DS also can play DS games from all the way back in 2004. That’s a 15 year old game library and the only restriction is that it can’t play games that require the GBA slot, which is a very limited restriction. So, really it’s the best DS console of them all.
Anyway, now is the time to buy one if you want one to play in the future. The price and availability is likely going to fluctuate upward, especially due to the complexity of the device and likelihood of them breaking, becoming cracked, etc.
Likewise, if you want a new 2DS, now is the time to buy. New 3DSs have skyrocketed and the 2DS will likewise when production ends.