I have one the same size... mine was off freecycle, but, in the course of finding that one, i was looking on ebay. Price seems to range from a fiver to about a ton.
Theyre between 12 and 1300 litres.
They get phased out, as the kerosene delivery people complain, but, so far as i can tell, they are within spec for all locations, unless "X" meters from a water course (ie the capacity is less than at which bunding is compulsory)
I believe tony has one for veg storage too.