Most recoil starters are easily removed from the engine housing with 3-4 screws. The rope is replaced and starter is reinstalled.
Some recoil starters are fastened to the engine cover with rivets. This requires removal of numerous screws, sheet metal, fuel tank , ect to be able to access the internals of recoil starter and change the rope. The engine will then need to be reassembled. This is substantially more time consuming than just removing a few simple screws or nuts hence the difference in price.
Many newer recoil starters do not offer replacement parts such as rewind springs, pawls, or reels. If these components have also failed, the entire recoil assembly may need to be replaced.