Robert Edmonds
EF5
Though for the vacationers, even if you know how many days you are gonna chase, you have no idea how many miles you are gonna put on, using your 750 miles a day (which I can definitely see being high) would merely mean a $400 or so difference in your budget for every $1 change in the price of gas. I'd say its pretty likely for a $400 error in budget to occur due to your 750 miles a day prediction being off, so rather gas is $3.00 a gallon or $4.00 is really no big deal.
$400 is a big deal when you're a grad student making ~18-20k a year. Now that I have setup my vehicle so I catch some sleep in it, my expenses largely reside in gas, food, shower, and data. Food being ~$15-20 a day, shower few dollars, data ~$50 a month, and gas ~$30-60 a tank (depending on price). I think from this I can say gas being $2 vs $4 has a big effect as to how frequent I go out for a trip to the plains.