I think conventional armour is way better in pk than new armours at the moment, not to mention they're not very expensive so you don't risk alot.
With the amount of time it takes to obtain trickster it needs to be alot better than third-age/zuriels but it isn't, the problem is though third-age and zuriel are really strong so it would be hard to imagine even stronger sets.
But I also don't think it's good idea to lower the amount of bloodcoins to obtain trickster etc because it's probably better for pkers to have long term goals.
Not sure how to balance it out, like I said I think the amount of bloodcoins per new items is pretty good, but the stats of the sets aren't.
I think the sets still require some more balancing.
1) Maybe added % of bloodcoins when killing someone in new set?
2) Increase stats?
3) Make it not lost on death but you need fix it with blood coins after death, the person who killed you gets bc? Idk