Secret second hobbies

How many of these are yours? I am researching my first purchase now. I started looking at amphibious planes and I see that I can get a good one for $100K plus. Any words of advice?
If it floats, flies, or fu**s, rent it.
I was looking at purchasing, right now things are out of control. Even Cessna 172s.
A friend just had his Piper engine overhauled. About 40k.
As mentions, paper trail and electronics.