After going from 2ds to 3ds XL, the difference is pretty huge.
I figure it's best to look for sales, and/or deals.
I bought my Yoshi 3ds XL (Green! Squee!) on sale for $199 with a 40 dollar gift card making it more akin to $169 which in turn helped me get a big Micro SD card (I already had the adapter for the micro SD to SD conversion) which was pretty awesome.
I don't know your financial situation, but there's the train of thought that you can probably upgrade later.
For what it's worth, the 2ds isn't a bad system, honestly. It's slightly smaller than an opened up 3ds XL, and only slightly larger than the 3ds xl when the xl is closed. Not quite sure how that works, but that's how it is.
The screen is a respectable size, and I like the ability to put the 2ds in sleep mode via a witch instead of closing the screens. It makes cleaning the screens easier, to say the least as you won't have to worry about opening up programs.
It can fit in a front pants pocket. At least my front pants pockets which don't seem to be larger than normal pants pockets.
The speaker is mono, weirdly. The grip, and the wedge shape are there for ergonomics it seems as it does feel comfortable.
If you don't mind not having 3d, it might be a decent alternative to the basic 3ds.
The 2ds is starting to get more accessory support, too.
Frankly, the only reason I upgraded was because the 3ds XL went on sale, and my clumsy self dropped my 2ds, and it started accumulating dust between the top screen and the plastic protector. If it weren't for those 2 events happening, I might not have upgraded at all.
That said, I've definitely started making use of the lanyard holes in both systems.
I don't regret upgrading at all, of course.