Back in 2018, I kept getting messages like "I know you mined with this GPU, so I will give you $20 CASH, TODAY!". While now most people send messages like "Is it still available, if so, I will pick it up ASAP". And you never get any low balls. If you list it for $100, normally you would get lowballed for $75 or $80, however you list for $100 and people pay $100, no questions asked. Meaning there is huge demand.
Send it signature required. If the buyer received the card and then tried to fraudulently do a chargeback you would win. I would also press charges for theft and let their local authorities and credit card company see if they wanted to add credit card fraud onto the theft charge.