The Lenovo Flex 14, a ‘value’ variant of the Lenovo Yoga, starts at just 499 Euro. It’s running Haswell, has a touchscreen and a good keyboard. The battery is removable and it does this screen rotation trick. Don’t try and turn it into a tablet though because the screen only turns about 270 degrees round!
I got some hands-on time with the Lenovo Flex 14, here’s the video. Images below. One thing I forgot to mention is that the Flex has an Nvidia discreet GPU option.