Complex sentence: The contestant selected an item, its price was revealed, and they then guessed whether it was one of the three more expensive items or one of the three less expensive items; this continued until either all six items were correctly placed or a mistake was discovered.
Split into simpler sentences: The contestant selected an item, its price was revealed, and they then guessed whether it was one of the three more expensive items or one of the three less expensive items. This continued until either all six items were correctly placed or a mistake was discovered.