My bag was peed on by a fellow passenger on the FRS (Victoria to Seattle) and I am unsure about compensation spending?

Long title but it is what happened. They were incredibly great about the whole process and refunded our tickets, however I talked to them and because I am flying out the offered to buy me a new duffle bag and 2 days worth of clothes for the return trip as we will not have time to replace them before we leave. My question is what is an appropriate amount to “spend”. I don’t want to be an asshole and have no intentions of buying Gucci, but also I’m not going to goodwill. My initial guess was between $500 and $700.