I have never purchased from Salearea but she has a good reputation as an honest vendor, and she posts loads of pictures so at least you know what you are buying.
I think that the stains, scuff marks and wear will probably not be a big problem, my black Carlyle was badly stained and scuffed but she cleaned up well.
I'm not sure about the shape though. This bag is very structured and the only way that I have been able to reshape the less structured, glove-tanned bags is by dunking them and then stuffing with towels. I haven't tried dunking an italian leather bag yet, so I don't know how that will work out.
Also the FS stamp means "Final Sale" or "As Is" so it may have some serious problems that will be difficult to fix.
I was unsuccessful in trying to replace the the missing long strap on my beechnut gracie and the cobbler advised against it. He said that it would be impossible to match the color and caviar pattern and I that I "could spend a lot of money and not be satisfied with the results." But it might be easier to do something for a black bag?
I have thought of getting a brushed gold chain strap but I am worried that it will wear along the edges at the top of the bag.
Just a word of advice, I love my sweet little Gracie but this is a very tiny bag! You might prefer something larger like a royalton.
My advice, if you can get the bag really cheap (like $10) it would be worth the gamble, but if the price goes up, I would wait for a better option to show up, JMO! Good luck!