A:Answer The actual feeling of the 3D effect differs from one individual to another, some feel sick or eyesore, and I'm totally fine even for hours.
Generally if you believe yourself to feel sick of 3D games less frequently and do not plan to play for long hours, the 3D effect is worth a try. But if you often find yourself giving up 3D games out of psychological reasons, then perhaps save money is a better choice.
ANOTHER factor is what games you plan to play, some games, especially ones with less "action" and ones that use overlook view, do not give 3D effects a great stage for you to enjoy. For example, Xenoblade and Monster Hunter are great in 3D, while 3D in Kirby: Triple Deluxe and Rune Factory 4 don't feel that cool in the few hours I've just started. Pokémon kind of goes between, there are systems designed for 3D, but mostly you just choose actions in rounds.
To sum up, I think 3D effects are a good thing to try, but there's no guarantee that you won't feel sick about it or the games you play may simply don't make much differences between 2D/3D.