I had mine FREE from the place next to Birkenhead tip. You have to collect it yourself I guess. I did anyway.
The soil available is there in huge "mountains" and you just help yourself to as much as you want - bring a 10 ton truck if you wish, they are glad to get rid of it I think. If you smile nicely the man there will drop it into a truck with his digger scoop. HOWEVER do not let him drop it into your ordinary domestic trailer. He dropped it into mine and it bent the axle!! Take a shovel and DIY.
The soil has been made from composted refuse of all types - well composted ie YEARS. They sort out the glass, brick & rubble and crush those BUT the soil will always contain some small bits of those. Looks odd but I have to say the soil is good quality and weed free because it has been composted for so long. I used it to build two rockeries and they are doing very nicely