The price is mostly for labor, though they may be charging you full retail for the plugs. And unless they specifically mentioned it, the price probably does not include wires. As someone mentioned, the engine is transverse-mounted, so the plugs are situated on the front and back. The front plugs are easy to get to. The rears are tougher, but not nightmarish. It just requires the removal of the strut tower brace to reach them. That should be three nuts on each end, sitting right on top of the inner fenders. I don’t think that extra step justifies the high price. You can get a set of platinum or iridium plugs at rock auto for $20-50, depending on brand and preference, which is probably about half of what the mechanic will charge you for parts. With the money you save, you can also get a new set of wires, a spark plug socket with universal joint, new ratchet handle, and still save over a hundred bucks. Good luck.