The cheapest way to get gravel is to visit a quarry or gravel wholesaler yourself with a trailer - my neighbour took me to one around here (not in your area I'm afraid) when I needed some, and they filled my 750kg trailer for 10€ (cash of course!), given how upset the tyres looked there must have been well over a ton in there as I've had a known 800kg in before now and they were absolutely fine then! Matt