The old, classic black Singer machines are great -- if you ONLY want to sew in a straight line. They don't offer automatic buttonholing, they don't offer any sort of zig-zag stitches, the really classic ones don't even have a reverse to lock the end of a line of stitching.
For any sort of modern sewing, just go to Sears and buy a modern machine.
For leather, you need a VERY heavy-duty machine made to sew leather. Your wife will NOT be using that machine for doing any dress making. And you will not find such a machine for anywhere near $200.