If you are paying full retail price for brand new batteries then you should be getting brand new fresh stock batteries that have not been previously installed in a bike, and have not been stored for an extended period of time.
If the batteries are for warranty replacement, or they are being sold at a discount price, then batteries taken from a new scooter should be a fair and honest trade.
Yes, he is charging full price for the batteries with a 6 month warranty.
Lenore Marginet