On many of the short-haul flights I've been on, you don't even get more space. Business Class is defined by a moveable curtain which they position according to how many Business Class seats they've sold at, so the same seat may be Business Class on one flight and Economy the next. The difference seems to be you get a different colour headrest and a slightly less inedible meal. But you do get free drinks, so you can try to make up the price difference there.