RX 580 8Gb & GTX 1060 6Gb are actually back down to €215-250 range (RX 570/580 4Gb are below 200).
The slightly better RX 590 is €275-290
I've also spotted this GTX 1070 for €300
https://www.caseking.de/inno3d-geforce-gtx-1070-twin-x2-8192-mb-gddr5-gci3-092.html?sPartner=185&utm_source=geizhals&utm_medium=cpc&utm_campaign=geizhals&campaign=psm/geizhals&wt_mc=preisvergleich.geizhals.feed
which would blow all 3 above out of the water.
Having said that - for 1080p or even 1440p
@60fps in the majority of titles the GTX 970's 3.5Gb VRAM is sufficient for now.
Just make sure to overclock it.
CES 2019 is 8-12. January & will hopefully have new GPU announcements, too.