All your items are high value so there is a risk attached to all. Even well established buyers have known to scam open a not as described case and received full refunds on returning a different item. It's the risk you take when selling .
eBay spend millions on advertising for new members to join which they do daily. Your buyer may have seen your item and opened an account purely to buy it. Being new they may not know how to reply to a message it's not an easy process.
You can cancel if you wish, but I'd imagine you'd receive bad feedback. It's your choice.
@emmal20