I'm saying this as the virtual Queen of Thrift and Second-hand shopping:
I still can't quite determine how deep the scratch goes, but I know from personal experience, that shoe and leather repair places often have difficulty matching unique metallic finishes or colors, which means you risk having a weird patch of differently-shaded leather on your bag.
You would probably have to ship it to Ferragamo for a perfect match, and that could probably mean the monetary difference between this bag, and the 67% bag.
I also think this scratch looks a little 'dry' at some of the edges, which means you would constantly have to be on top of this with a leather moisturizer or wipes, to keep it from drying out and becoming a true crack.
I would pass on this bag, unless you can get the seller to agree that she will accept a return, provided you just examine the scratch in-person, and don't try to fix it yourself.
Or be patient and wait. If this bag is on eBay, and you've already seen a second bag at another price point, it means there will very likely be more of these in the future, if you are willing to be patient. That could mean waiting another 8-12 months for this bag.