Wisdom is Just Another Name for Common Sense
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First of all, I strongly urge you to reconsider your plan to cover the 1,400 miles between Atlanta and Bar Harbor in only 2 days. That would be too much even if you had open road all the way, when in fact you'll be driving through some of the most congested traffic in the US. Three days is much more reasonable. Secondly, the difference between $3/gal gas and $4/gal gas means an extra $140 on the cost of the entire trip. That's significant, but should hardly be a budget buster on a trip of this magnitude. And gas is only going to get more and more expensive over the next several years. On the other hand, as fewer and fewer people hit the roads because of the perceived cost of gas and very real increases in the cost of food and other financial problems, hotels, motels and other accommodations should be more prone to lower their charges, but you'll just have to shop wisely. I can't help you with finding lobster in the Bar Harbor area, but I used to live and work in the Portsmouth, NH area and can recommend two relatively low cost and old fashioned lobster houses in that area: Newick's in Dover, NH and Warren's in Kittery, ME.
AZBuck