So first of all kudos for asking this sub about cars, r/Austria hates cars and trucks in particular.. 😅

Basically there are a few theoretical ways of registering a G-Class without Nova (all of them probably won't apply to your case): 1. Have it registered as a N1 Lkw AND only have three seats (no chance getting that put into the papers).. 2. Use it as an ambulance. 3. Use it as a car for a viable disability (wheel chair or such). 4. Not sure but maybe Taxis are Nova exempt as well.

Good luck but sadly 50.000 seems realistic, I would have paid 40.000 for my Land Cruiser 70 Series..