You'll get 344 arena points in 5v5 anywhere from 0-1500 rating whether you win or lose. Just do 10 games.

I had some success last season doing 3x elemental shaman in 3v3, way undergeared. Got to 1550 and was able to get all my accessories. Of course, now that's just belt and boots. A lot of dumb comps 0-1500 are easy to counter, like double healer. You can hex and wind shear both healers and kill the rogue/warrior or whatever. There will also be a lot of bads playing legit comps (like RMP) that you can beat. But past 1500 a legit comp played right can't really be beaten due to all the counters.