It looks like these are carried by Target.
I'll try to check em out next time I'm there.
They will probably be approximately the same weight as Crocks.
I find neoprene fin socks better for crossing streams and OK as camp shoes. Mine weigh 4 ounces, a little less than crocks. They help keep the cold water chill away and don't slip around the way crocks do.
They are also warm as socks inside hiking shoes in cold wet environments where the trail goes through a lot of water, eg. those annoying trails that cross back and forth across streams.
They don't have the hard sole of crocks, so you won't want to do much walking in them.