PC Gold Grim Cesta (off hand)

+12 energy {req 11 death}
improves skill recharge using death magic skills {19%}
AR+5 {while hp is above 50%}

Don't know much about offhands.

IF:
offhands CAN ONLY have skill recharge on them, then maybe ~ 10-20K

IF:
offhands CAN HAVE BOTH casting and recharge, then probably ~ 2-5K

most the time, stave are the easiest to sell, and worth more because they can be customized w/ mods.