How should I go about selling a bunch of high(ish) end art prints?

A friend has asked me to help her sell several photos and paintings. Most are nature photographs by artists such as Thomas Mangelsen and some are limited edition reprints of paintings (mostly by Bev Doolittle). All of them are framed, signed and numbered and include certificates of authenticity. They seem somewhat pricey and probably don’t have a huge group of potential buyers.I did some preliminary looking on ebay and a couple of other sites, but I am wondering if there are any reputable sites that specialize is this type of thing.