I have Asus Zennbook UX31A (I got only 4 GB of ram, newer version have 8GB) and it works almost perfectly with Ubuntu 14.04 (and older, only thing that does not work is ambient light detector).
At least here in Finland they cost about 1100 euros (http://www.verkkokauppa.com/fi/product/36916/dnqkg/Asus-Zenb...). While it does not have VGA output, it comes with HDMI->VGA adapter.