I'm not sure what distance you're moving or if you have pets/kids to take into consideration, but I recently completed a 1,400 mile move with my SO, dog, and cat for around $1,200.
We don't have a whole lot of stuff, and we fit everything into a mid-sized Budget moving truck, but it sounds like you've already got that part covered.
In terms of vehicles, it was definitely cheaper for us to drive both vehicles to the new location. A friend offered to drive my car, and we opted to hook a trailer to the moving truck for my SO's car. Fuel costs to move my car were less than $150, and would be much less now that gas prices have dropped.
Gas Buddy has a great feature for helping estimate fuel cost for a trip at
http://www.gasbuddy.com/Trip_Calculator.aspx.
Because we didn't want to deal with driving the truck + trailer into more populated areas or trying to find hotel rooms that were okay with dogs and cats, we slept in truck stops in the car that was on the trailer. So, our lodging costs were $0. I have a whole new appreciation for truck stops now. They offer free lodging (in your own vehicle), competitive fuel prices, relatively inexpensive prepared food, showers, and grassy areas for pets (usually). I'm not sure how cheap you're looking to get, but driving a fuel efficient vehicle and sleeping in your car is definitely a
really cheap way to go. I found a list of truck stops for our trip on
http://www.findfuelstops.com/. I just searched for "truck stops" + whichever interstate we were on, and the #1 results is usually from the findfuelstops website.
In terms of dubious furniture, my rule for myself is if I don't love it, I donate it. We ended up hauling a lot of stuff to our new place and then immediately donating it after we moved. I also donated a ton of stuff before we moved, and there hasn't been anything yet where I think, "boy, I wish I had that __ I donated." For the most part, I can't even remember what I got rid of.
As far as moving tips go, I took the advice of someone else and numbered all of my boxes and then wrote the box number and a description of what was in each box in a notebook. If other people are moving your things, this could definitely help you figure out if you're missing a box on the other side. I'm a little bit of a haphazard packer, so it helps me at least feel more organized about the packing.
Anyway, best of luck in your move!