Gravel is sold by volume (cubic yard), not weight (otherwise they would never sell gravel after a rainfall!). Usually a dump truck can carry 10-14 yards (at least the ones around here).
My cost varies with mainly with the cost of the fuel required to run the dump truck. In my case, it costs around $250-300 for a 14 yard truck to deliver a full load of material. I wouldn't bother getting anything other than a full load, given the trucking cost accounts for about a 1/3 of that price, they might as well fill it up. I can always think of a use for the stuff here.
The material costs vary, of course, but not by much, usually only a $1-2/yard difference. The trucking costs vary widely, try to find a place that has exactly the material you want close to where you are. I used 1-1/4" stone for my roadways and driveway; 3/8" for walking paths for people and horses; 3/4" for sub-base under a large patio (which will have sand or stone shavings on top prior to installing paving stones), and white limestone sand for my wife's riding area (she trains horses).
There are various grades of gravel, it's usually sold by size. Depending on who's doing the stone crushing, you typical have sizes ranging from 3/8" to 1-1/4", and some places will sell raw stone (up to 4") for road sub-base.
Almost every gravel pit will sell something called 'processed gravel' which is a mixture of different sized crushed stone and sand, designed to compact really well. This stuff does compact really nice and hard, but it doesn't drain too well after it's been compacted, so you must build a slope on your driveway or a crown on the top of your road to direct rainwater. If you're happy with this, then processed gravel is the way to go, because the material cost is probably the lowest of all your choices.
If you want a flat road with no slopes or crowns, then you need to build the water handling slopes underneath the material, lay separation fabric, then spread crushed stone, not processed gravel. I went this route, and took my time to create all the proper slopes in my clay sub-base. I waited for several heavy rains to be sure the drainage was effective before I brought in any gravel.
In any case, you should run a compacter (vibratory roller or plate compacter) over your finished work. If you don't, it will eventually compact itself from rainfall and use, but that will take months or years. I rent a vibratory roller (the ride-on type) for around $100-150/day depending on the size of the roller.
I've found that following all of this advice gives really good results; I have no problem supporting very heavy vehicles (including full dump trucks!) with no ruts resulting. My neighbors keep coming over asking where I learned to do this... ...all of the info came from
Paving Expert. I was trying to learn the best way to prepare for a paved surface, but I'm actualy so happy with the way my crushed stone looks and works, I may never go to the pavement. I'll decide next year after we've gone through a winter.
As for winter, think about how you're going to remove the snow. Make sure your plow has skid shoes on it, and they are extended far enough down so that the plow doesn't dig into the gravel, otherwise you'll be leveling it all out again in the spring.
