Complex sentence: As the Robot Wars television series evolved and grew, Razer's design was revised and refined to counter weaknesses and take advantage of rule changes; by series 4, Lewis estimated that Razer had taken 1,500 hours to build, at a cost of £1,600.
Split into simpler sentences: As the Robot Wars television series evolved and grew, the design of Razer was revised and refined to counter weaknesses and take advantage of rule changes. By series 4, Lewis estimated that Razer had taken 1,500 hours to build, at a cost of £1,600.