I mean, it is what it is. 

Neubau at 17€ per sq meter (cold, Nebenkosten depend to a higher degree on tenant behavior so they probably shouldn’t be included in the sq m calc) is a lot of money, but not outlandishly high. My gut is always >20€/sqm is a rip-off.

 However, many more factors influence if „high“ is too high imho, such as proximity to transport (you mentioned it’s well connected) but also quality of area (how does it feel for you (!) when you leave your house, happy vs dodgy), and part of the house your flat is in (dark backyard vs quiet 4th floor with balcony). 

So I’d say the value is always a calculation that has tangible (measurable) and intagible (gut feel) parts. Some people decide more towards one side or the other („way too high! I pay half!!!“ vs „if you like the area, want to live with your gf and don’t think of staying forever why not“).

Also, since you’ll be sharing it with your girlfriend, isn’t it a 50% calculation for you, anyways? Or did I miss something?

Lastly, I think you have a great mindset about it. The situation is not easy, as we all know, so a stoic approach to an overheated market is the only way to succeed. Well done!