I haven't really had a look around but if they are going for $300, then yeah.
I usually use that formula to price second-hand gear.
In the interest of trying to upsell you to something you didn't want, id do the master and slave for $200 :p, I think at the time I brought them they were $700 for the pair.
Both are running perfect and are in use but I am looking at upgrading to a Kore 7 to do KH monitoring as well.