7 plus 256GB

To my knowledge, iPhone 7 plus currently (buying as new from Apple) has 32 or 128GB capacity.

But when it was released (ad the end of 2016) there was also a 256GB model.

Take a look here: Identify your iPhone model - Apple Support

Regards

Giulio

there was a 256gb model but towards the end of 2017 that model was pulled from the lineup. If you wanting to buy one you can contact your cell provider and see if they are still able to get one for you. I got lucky when I got mine because there were only 5 left company wide (I went through the authorized retailer that I work for). It might also be possible if to find one through the Facebook market place if someone is selling one, or possibly a cell phone repair place.

The Project RED version. You are correct.

Probably would cost more too, because it was a limited run.

I'd be wary of getting it off the Internet. There have been stories of the phone being reported as stolen right after a private sale.