Capitalist might buy it from you (he likes double damage reduction and skeletons). I typically sell -2/-2 shields for around 100K, sometimes more, sometimes less. I'd say 100K is a good price for this one (good req, popular graphic), but it is tough to find a buyer for these shields most of the time.
depending on how much the buyer likes skull shields....this can go from 100k up till like 300k i think.
but most likely around the 100-150k range.
hope this helps!