I think which signature you have good for you no one interested to buy your signature any more
It indeed is useless to try get a better price for your Signature, I think it is amazing we even get something for posts we make, and 50-60 posts is not going to bring you far as much as advertising goes...
Same thing for people who think they can make 2000+ Posts a month, it just is not possible, or you are posting random crap, and even then you are 3 hours a day posting on this forum.