How would placing all of it in one corner of the yard be much different than it being in the raised beds? I can't see where contamination would be any more an issue if piled out of the way for several months.

That is about 4 cubic yards of soil if your beds are about 1 foot deep and that is enough to make 4 pickup truck loads. If you bought it by the bag, then it is quite expensive. I get mine by the cubic yard for $25 a load from a local nursery.