Purchase advice A2 motorcycle Harz Tour

We want to drive next year with buddies for 7 days in the Harz. I have an A2 driver’s license, but only a 125 MZ ETZ. The buddies are traveling on large machines (80 – 100 HP). I had thought about renting a motorcycle for the time to borrow. However, the rental prices are 80 – 100 € per day. I would rather invest the money in my own motorcycle. That would also have the advantage that I can get familiar with the box before. Which motorcycle is recommended to use the big bike. Is there a good time for 2000 €? I am skilled in craftsmanship and I dare to hand myself. I had thought about buying a Suzuki GS 500. It’s really cheap. However, I’m not sure if this is a fun machine for the mountains. I like the Yamaha SR 500 very well from the look. But here’s the performance and my budget a little short.