Well, Id price a new one and see what they go for and compare. then determine if the autograph (if it's authentic) is worth the diff to you.. Im not sure what the go for new and without proof of authentication on sig, it may not be worth alot more than a stock one. (I couldnt see the listing, so if there is proof then disregard.) But it would be a cool guitar to have and the sig would be a good conversation piece.
Also, welcome to the forum!!