Or a 1070ti for about 400 euros = https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F264518171122
Ok that is about 444 euros but I reckon you could find one of those for the 400 euro limit mate.
@Mowtin yes I remember that story, read it here, couple of sentences down it mentions what you said = https://www.nbcnews.com/nightly-news/father-says-baby-who-survived-13-hour-car-crash-ordeal-n321791
Just checked recently that my 6700k is bottle necking my 2080ti by 36.5 percent. If I pop a 9900k in my pc it'll bottleneck my ti by 0.01 percent. Go figure :( i wonder if the new 3080ti's will need the next gen cpu?