Mystic stamps over values their stamps by a considerable amount, after all they are there to make a profit. Scotts value will be based on a almost perfectly centered SMQ 90+ stamp. Few will have this centering, yours is an off center stamp. The value of typical 219D will be less than $1. Checking eBay
the value of your stamp, based on past sales, is about 25¢ if in good condition, yours has a pulled perforation at top right so maybe a little less.