Welcome to FT. I'm only 6' (1.82m), but I still find E- unbareable (thankfully, within China, I'm pretty adept at snagging exit row seating). So, I understand your frustration.

In spite of the fact that you are based in Europe, I think UA MP would be a better frequent flyer program for you than Miles and More because the latter is not well suited for economy class travelers.

So, I suggest you part ways with LH and join our ranks. In the meantime, there are other ways to get E+ that don't entail paying $300. First, I suggest you request a status comp to UA (there's a long thread explaining how to do this).

If that fails, many people in these parts have the ability to bestow 3P status upon you, which will qualify you for E+ seating. Unfortunately for you, most of the action takes place in the Coupon Connection forum, which you can't access until you post ~100 times and have been around here for ~3 months.

That said, I wouldn't be surprised if some of the folks around here contact you directly concerning this option.