a more heavy-handed fine.
You already received any benefit for the first-ticket-ever angle - the cop wrote you up for 8 over instead of 10 over, which likely makes a decent difference in the amount of the ticket and the severity of the ticket on your record.
The speed-trap angle will not work and will come off as whiny with the risk to become belligerent.
Pay the fine and move on...and don't drive 50 mph in a 40-mph zone.