*laughs uncontrollably*
Yeah a garundamnteed way to get an assload of shards is to run a hard raid with your level 29's trust me.
I ran out of ass shards before the weekly reset, after I had done 3 hard raids I was sitting on 50-60 shards, by time I done the Nightfalls and Weekly heroics and the dailies, I was in the 70-80 range, that's not including all the duplicate kit that I had no other choice but to shard, plus the third worse case scenario of getting about 10 shards/energies for completing a Nightfall.
You will get your investment back in spades easily.
Only thing that sucks, is the material farming, but here's hoping Bungie fix that soon.