Apple iPhone 6s, 6s Plus: Should you upgrade? It depends

Some will always want the latest and greatest iPhones; Apple

Refurbished Apple iPhone 6S Plus (Space Gray, 16GB) - (Unlocked) Excellent

Apple iPhone 7 vs. iPhone 6s: Should You Upgrade?

Upgrading From an iPhone 6S to an iPhone 6S Plus

iPhone SE Vs iPhone 6S Review: Which Should You Buy?

Here are the coolest things you can do with the iPhone 6S and 6S Plus - The Verge

Refurbished Apple iPhone 6S Plus (Rose Gold, 16GB) - (Unlocked) Good

With iOS 13 update, goodbye iPhone 6. Other budget options from Apple

Review: Apple's iPhone 6s + iPhone 6s Plus are nice but definitely not mandatory upgrades [Video] - 9to5Mac

Apple iPhone 6 price: How much will it cost in the United Kingdom?, The Independent

If you have an iPhone 6 or 7, Apple owes you some cash

How Much Is Your iPhone 6 / 6 Plus / 6s / 6s Plus Worth Now?

Review: Apple's iPhone 6s + iPhone 6s Plus are nice but definitely not mandatory upgrades [Video] - 9to5Mac