So sorry to be responding sooo late. I've not tried the Amazon slices, but Fermin is a brand I know well. I have a Fermin jamon hanging in my cellar waiting for guest next weekend. Buying a whole ham, it runs probably $30/lb after removing skin, oxidized fat, and bone (and that's great sale price). Some of the top of the line jamon runs well over $1k. So it's pricey, but excellent. The Amazon stuff at $10/ oz is fine for a quick sampling or serving with a small number of guest. We'll have 9 staying for several days, so we'll eat maybe half of it.
I'm also making a several tapas... tortilla, empanadas, chorizo and chickpeas... and a case of Cava and a case of Rioja. One of the guest is cooking paella one night. Should be good food for a group of close friends.