Topps Archives and Leaf (Panini also in general to an extent) have kinda ruined the 1/1 market. As others have said, they aren't really that special anymore, as there are 1/1's all over the place. Leaf specifically has made a mess of things with all the products they keep releasing, all "limited...
I've sold some cards through that site. Seems to work well, is trustworthy. I haven't had any issues and they sent the money to me several days after the sale.