Search:

At some point you have to take a step back and evaluate whether you're still in control or not.
As long as you have a plan and a realistic budget, you're fine.

But I've known guys who got to the...

What I restore, I use for a while and then I sell it. The hobby pays for itself. My wife doesn't mind because she knows it's a zero sum hobby.

It's normal to buy some stuff when you are starting out.
But if you see yourself falling into a pattern of buying without a particular reason, it's best to reassess what you are doing.