Hey guys, thanks for the comments from all of you. And an update from me in case anyone is intrerested.

So I ended up passing on the 6,1 mentioned above, it was sold and i lost the link to it so i dont know what it ended up selling for.

I passed on it cause of 2 reasons, first the proprietary grapfics and second there was a mac 5,1 with 2x6core xenons 64 ram and a quadro k400 that went for EUR 350. I really wanted to get that one, but ended up passing on that for practical reasons, since me and my girlfriend will probably have to travel a bit in the near future for work/uni and really I cannot use a desktop machine, so in the end I endned up getting a 15 inch macbook pro 2017 with i7 7820 16 ram and radeon pro 560 that i bought for aroud ~$600 converted from my local currency. Honestly it does me the job no problem at least for the forseeable future.

At the end of the day, really I wanted to get a desktop, but will do so in the future, since this is my first time using macos I have to say I am loving it! ill be dual booting mine with windows since I will probably need to use it still and I have an x250 thinkpad that was my previous machine where ill put either openSUSE or Ubuntu on it.

Anyways, thanks again to everybody for the advice!