>>7142252133DS, 3DS XL, and 2DS are irrelevant. You are wasting your money buying them in this day and age. They are literally just worse ergonomics, worse performance, worse when hacked, can't play all 3DS games, do not have eye tracking for the models that do have 3D, and can't run certain homebrew plugins like NTR for screenshots or screen capture on certain games.
N2DS has no 3D but the better performance of the "New" models. This was primarily meant for children with how it was designed. It's typically the cheapest out of all of them.
N2DS XL is the same thing, no 3D but better performance of the "New" models, but it is more like a traditional DS with the clamshell design.
N3DS is the best in terms of a deal as it has interchangeable faceplates (Many people make aftermarket ones now because the officials are so expensive), has eye tracking 3D, and the normal size of a 3DS. In the Japanese (and I think European) markets these are called "LL" models. In America these were only available during Black Friday for one single year making them very expensive. We're talking $400-1000 used.
N3DS XL is the "I couldn't afford the N3DS" option. Bigger screens and slightly better ergonomics due to the size in exchange for no faceplates.
In general the XL models have worse screens and pixel density compared to the base models. Games were designed around the base model screens so when you use an XL it's just blowing the image up a bit. This is in contrast to the DSi XL which is objectively the best iteration of the DSi as that had proper scaling.
The issue with buying out-of-region 3DSes like the LL is that you can't system transfer to them if you have data on an older 3DS, even though we can region change 3DSes now it breaks the eShop if the thing has ever been used before, and region changing also breaks the internal native DSi aspect of a 3DS so you can't natively run DS games on the thing anymore.
