Just a heads up this excellent network-free dual SIM Android phone is £99 (Usually £129) on Amazon today.
Had mine since Xmas and it's a cracking phone. Dual SIM is nice (so you can have a separate data package running).
After trying to equip my feckless son with a temporary phone (seems teenagers nowadays go through phones faster than shoes !) and discovering that out of 12 working phones, not a single one could be pressed into service (all dumped in disgust) I have vowed to never ever buy a network locked phone again.
(The biggest biscuit taking was EE who wanted £30 to unlock a £5 handset bought from "Orange". Remind me again, who are EE ?)