Whatever you do - do not return any of the money to them. That is how the scam works. They give you too much and ask the difference be returned and by that time cheque bounces and you have sent your money to them. Let them know they can have the difference when they arrive for care. Even if the cheque appears to cash now pretend it is not in your account as it will most likely be removed nsf or cancelled by sender soon enough. This scam has been around for many years.