For frost r10 shoulders and gloves are BIS together with bloodvine and 300 tailoring. For fire r10 shoulders and boots are very strong, but a little bit weaker than t2,5 boots and shoulders, because you loose spell pen and spell damage.
I'd not bother doing r10 for these items any more, because the effort is so huge. The r14 dagger is BIS until naxx, but also not worth the time spent.