These prices and weights were easily pulled off of various websites.
I don't know which weight you used for the Hacker C50, but based on the above you may have used Hacker's listed weight of 529 grams.
Please note that this weight is misleading, as it does not include the prop driver, washer and nut. (But you wouln't fly without them.) Add approx. 30 grams for these items. Even the Competition version is more than 550 grams including these items.
Magne