Unless that buyer really is a "Maria Sharapova" (the landscape gardener based in Arizona, and not the tennis player), it depends. If that buyer is hoping to make money off the better known Maria Sharapova (the professional tennis player)...well good luck with that
ThanksIf u r confident on the traffic , just keep it ..
In order to file a UDRP complaint with a UDRP provider, the costs often start around US$1,000 to $2,000
so keep a buy now for 500$ or so .. so its always a good choice for buyer to buy it rather than to go for udrp
but make sure the domain name is not used in "bad faith" just to be on a good note always