Just got a Oneplus 6 which is a great phone with very decent camera. Fast unfussy software, great design, fantastic reliability, plenty of good used examples going for £200 plus. Got a pristine one in white for £240
Apple don't do a dual-SIM phone, do they? They do normal SIM and eSIM, but not all providers do eSIMs. Plus they're on 2018 phones onwards, unlikely to be available for under £500...
For Sale - Unlocked Xiaomi Mi8 in Blue - 6/64 GB - UK Version I have for sale my 4 month old Xiaomi Mi 8 in Blue. –– ADVERTISEMENT –– It is the UK Version of the phone as it was a 3 contract phone and I am only selling as I have upgraded to the Mi Mix4 5G. It comes boxed with all original accessories and is in fantastic condition. It is running... www.avforums.com
Well under budget for you !!