Why the price difference for the same GPU Model, in the Same Manufacturer?

Hi all!


I Want to upgrade my current GPU GTX 1060 for a new Graphics GPU GTX 1080.
I'm rendering 4k Videos so my current GPU had to be overclocked and it would do the work (slowly and with lots of software optimization).
I live in Portugal and I want to buy it from Portuguese stores because of Warranty issues that might come up.
So far, I've searched a little and found this page (link at the end) which gathers some Portuguese stores offers together (it's easier to sort like this). However, I don't understand why the same manufacturer, produces several models of the same GPU with same memory capacity, etc, and sells them for different prices.
I Want to buy an ASUS 1080 but I find 100€ price diference between the same cards (only visible diference is the cooler), which I don't think it's worth the difference.

Can you guys please help me choose the best 1080? I don't mind to pay the extra 100€ but they have to be justified at least.

My selection: https://www.tecmagnet.com/produtos/p...eco=+preco+ASC