I've been buying 3DSes off of Kijii to flip. My latest one was a new looking ALBW one with a charger and two cart games - Super Smash Bros and PKMN Omega Ruby. $220.
The cheapest I've seen is the 2DS going for $75 locally - I personally can't get rid of mine, even though it has cfw on it. Dunno why, but the demand for 2DSes is almost non-existent.
Edit: Finally took my 2DS off the market and am going to send it to my girlfriend in the States. Cheap gaming, yo!