The +30 is part of the shield but not a mod? Oh well. In that case, I'd say its worth a couple plat, tops. If it has "of Fortitude" in the name though, that would mean you can take out the +30, which is, as stated above, worth ~10k.
"I need money for pot, booze and women. Hey, at least I'm honest." -- A street person in Vancouver, BC