Would buying a 3DS be worthwhile in my situation?

To summarise my current situation, I don't have a lot of money and I am currently getting ready for a lot of exams. So I kind of wanted something that I could easily pick up for 5 minutes and put away again whilst i'm revising (to keep me sane).

So I thought about getting a 2ds, the only thing is there are only a few games that I'm insistent on buying (Fire Emblem:Awakening, Pokemon X/Y and OR/AS), a few others had my attention including the new Smash Bros and Monster Hunter, but not as much as the previously mentioned.

I've never been entirely interested in platformers so is there really any other reason or games that would make me buy a 2DS, or would I just be wasting £100? Also, what is the replayability and overall game duration of the games mentioned and are there any games you'd recommend?

None of the games you mention can be played in short bursts except maybe Smash Bros.

If you're just looking to distract yourself a bit during exams, find something else. If you're intending to buy one anyways at some point, then yes, you might as well get it now.

yes you should.