Very, very hard to give a valuation on something without better pictures. Photos of both sides would be nice! Based on what you have presented, I would guess the value to be between $2500 and $4500. That's a pretty wide spread but there are so many unknown variables!
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You might try actually SHOWING her some money. Ypou would be surprised what happenens when you ACTUALLY put crisp 100 dollar bills in their(her) hands. An old picker told me this. He would tell them "stop me when it is too much". lol It worked for him. Don't be shy. Good luck, Dave