Our last big move was 11 years ago. We were a family of six (four little kids), moving out of an 1100-sq-ft home. We rented and filled a whole 26' Penske truck. We brought most of our appliances with us, and I used Sketchup to plan how we would fit everything in the truck. In one section of the truck, I built a platform 5' off the floor, which allowed us to more effectively stack boxes all the way to the ceiling. If memory serves, it was about $2k for the truck rental, but the gas! Oh, the gas was probably another $1k. We also rented a car trailer.
If you go this route, I'd recommend getting the car trailer (where the whole car sits on the trailer), rather than the dolly (where the car's front wheels are on the trailer and the rear wheels are on the ground). It makes maneuvering much easier if you have to back up.
Another option: Several years ago, my brother (family of ten) moved using ABF (upack.com). They park a 28' semi trailer in front of your house for a few days, you fill it up, they drive it to your new house, you have a few days to unload it. You pay by the linear foot of trailer that you use. In theory, if you don't use the whole trailer, ABF can use the remaining space for other freight that's going the same direction. Advantages: you don't have to drive it, and it's a bit bigger than the equivalent Penske or Uhaul. Disadvantages: less time flexibility, more expensive (at least, last time I checked). Also, they have a calculator to estimate how much of a trailer you'll need, and from what I've heard, it underestimates what you'll use, and exceeding the space you reserved costs a bunch extra. On our next move, this is likely the approach I'd prefer.
Other thoughts: Before you move, declutter. Get rid of stuff. Purge. Sell stuff that will be easy to replace in your new location. If you take the cost of an ABF trailer and divide it by the internal volume, it comes out to something like $4/cubic foot. So, a rule of thumb: for an item you want to move, look at its volume, multiply it by 4, and guess what it would cost to replace it in your new place. Or whether you'd even bother replacing it. Suddenly, a lot of furniture gets a lot harder to justify moving. So do box springs, guest beds, bulky kids' toys, sawhorses, work benches, patio furniture, trash cans, bikes, fertilizer spreaders, tomato cages, wheelbarrows, fire pits, exercise equipment, floor lamps, table lamps, general home decor....the list goes on.
We're hoping to move in a year or two, and now that we're a family of 8 (including three teenagers!) in a clown-sized house, the prospect of moving all that stuff is very daunting indeed. The more you can declutter, the less stress you'll have.
Other advice: start packing WAY in advance, and have everything ready to go on the truck before it arrives. That way, you'll make the best use of the help you have, and you may avoid the need for extra helpers altogether. Loading stuff on the truck should be the second-fastest part of moving (unloading being faster). The only things NOT boxed up on moving day should be 1) your cleaning supplies and 2) stuff that can't practically be boxed up.
Planning how to pack things in the truck was a huge boon for us, because it allowed us to take everything we wanted. That truck was packed tight enough that without that planning there's no way it would have all fit.
