This is a cross section of a Roll Royce Trent 1000. This engine was first introduced in 2006 for the new 787-8 maiden flight. This engine cost 41.7 million because of its modern turbo fan design.
As you can see the first blades at the front of the engine are bigger than the second one behind it, The engine is very economical. The engine is used on mostly used 787 :)