SD9 is notorious for losing things - from little and insignificant to expensive and important.
For instance, we recently went home to visit my family. Her mom had grounded her from her iPod so SD14 let her borrow hers for the trip. During the trip, she left it in the bathroom of the frozen yogurt shop, on the table of the frozen yogurt shop (both times it was brought to her by someone who'd found it), before eventually leaving it behind in California altogether.
Had it been her iPod, not her sisters, my DH would have had her just go without it until we went back to CA. Since it belonged to SD14, DH had my mom mail it to us and took the shipping cost out of SD's allowance.
SD also has a retainer (she's had it about 2 months) that she frequently misplaces. Fortunately it's always in a place where it can be found again (like one of her two homes). Last night, DH got a text from BM that SD lost her retainer while at a restuarant with a friend and each parent would have to pay $150 to replace it. DH's initial reaction was, "Sorry, she's going to have to go without. Even if I had the money to pay for it, she needs to learn there are consequences for being so irresponsible with her things." I agree with him. He hasn't responded to BM yet.
What would you do in this situation?
ETA: While I was typing this, DH drafted a text to BM that he would pay for it in January when he has his HSA available for reimbursement.