I'm possibly going to waste $200 on gas for driving instead of flying.
Are you sure that driving is the best option if it will cost you this much in gas?
Yes, I thought about it and you've successfully influenced me to just drive to get there.
I'm pleased that you are taking my advice but I think you misunderstood as sometimes driving isn't always the best option. If it will cost you less to fly than to drive, then you should go with the flying option.
A. I already bought the $200 in gas and I'm ready to drive.
I can understand that you already purchased the gas this time, but you shouldn't get in the habit of wasting money. You should try to take the most efficient form of travel going forward.