But (a) that would then be a different list, the 100 best bargains, not the 100 best universities, and (b) if you really want to measure what it costs, you have to factor in European taxes, since you have to pay more unless you are an EU resident.
I come from Trinidad & Tobago, and most of my schoolmates went to American universities for this reason: UK universities are completely unattainable to a non-western income.