I suspect that this has already been changed internally, but the magical items you get with crystal are WAY too expensive in gold terms to be of any use compared with how much they do.  I've never used a single one despite having lots of crystal because the gold charged is extortionate.

So I think they should be a) a lot more powerful so you'd actually want to use them (currently a cheap bit of armour and some boots will do the same job) and cost a lot less gold.  If crystal costs are kept as they are then only your elite troops can get them anyway.