https://www.theguardian.com/technology/2017/sep/15/iphone-8-buy-cheapest-offers-cheap-sim-only-deal-cost

Don’t be suckered in: navigating the multitude offers reveals buying an iPhone 8 outright and signing up to a cheap sim-only deal is the most cost-effective option

The iPhone 8 is available to pre-order from today, but don’t be distracted by flashy offers with low upfront costs and a high monthly fee: the cheapest way to get one is still simply buying it outright from Apple or another retailer, and taking out a low cost sim-only contract.