iPhone 13 - 128GB - Blue/Green/Pink: £679.99 at eBay Tesco Outlet / eBay

Cheapest price around that I can see from an established store.

Link to green:

NEW Apple MNGK3B/A iPhone 13 5G 6.1" Smartphone 128GB Unlocked SIM-Free Green | eBay

Link to pink:

NEW Apple MLPH3B/A iPhone 13 5G 6.1" SIM-Free Smartphone 128GB Unlocked - Pink | eBay

There are also some open box green ones for £619.89:

Apple MNGK3B/A iPhone 13 5G 6.1" Smartphone 128GB Unlocked SIM-Free Green A | eBay

Generic iPhone blurb:

Cinematic mode automatically creates beautiful depth effects and focus transitions

Just start recording and Cinematic mode will hold focus on your subject while creating a beautiful depth-of-field effect all around them. Cinematic mode can also anticipate when a prominent new subject is about to enter the scene and automatically shift focus when they do. Now you can effortlessly create videos that look and feel like the movies. Want to change the focus or adjust the blur after shooting wraps? No problem. iPhone 13 lets you do it with a few taps and swipes.

Take a great photo without lifting a finger

Night mode senses low-light scenes and automatically adjusts to take bright, clear photos with amazingly rich colors. Portrait mode artfully blurs the background to put the focus on your subject. You can try out six creative lighting effects with a swipe. Smart HDR 4 recognizes up to four different people in a scene and optimizes contrast, lighting, and even skin tones for each one. Deep Fusion activates in mid- to low-light scenes. It analyzes multiple exposures pixel by pixel to capture the subtlest textures, patterns, and details. The Ultra Wide camera gives you a wide field of view even when you're right up close to what you're shooting. So you can capture more of the scene without stepping back

A camera with a style all your own

Photographic Styles create a personal look for your photos. But unlike filters, styles selectively apply adjustments to the right areas, while preserving skin tones. Choose Vibrant to make photos bright and vivid. Rich Contrast for darker shadows and deeper colors. Warm or Cool to accentuate golden or blue undertones. Preset, ready, go!

Super Retina XDR display

iPhone 13 features a cinema standard wide color gamut, displaying colors just as filmmakers intended. And with precise color accuracy, everything on the screen looks remarkably natural. The Super Retina XDR display has an ultrahigh pixel density, so photos, videos, text - whatever you're viewing - looks extra-sharp. And the display is even more expansive, thanks to a smaller TrueDepth camera area.

A15 Bionic chip

The lightning-fast A15 Bionic powers Cinematic mode, Photographic Styles, Live Text, and more. Its Secure Enclave locks down personal info like your Face ID data and contacts. And it's more efficient, helping to deliver longer battery life.

More 5G bands for 5G speed in more places

The world is quickly moving to 5G. Streaming, downloading - everything happens so much faster. 5G is even fast enough for serious multiplayer gaming, sharing AR videos, and more. With Smart Data mode, iPhone 13 will downshift automatically to save power when you don't need all that speed.

Hope this helps someone out