I have battling hobbies, making it hard to know which to invest in when I end up with a little extra money. Good guitars are expensive. I lust after a Martin HD-28, but it's $2400, and the D-45V I'd really love to have is $8200. That's a lot of camera gear, but I do play guitar every day. I settled on a lesser model that sounds quite nice and I'm not afraid to play it for fear of dinging it.
I save my pocket change and end up with ~$300 at the end of the year, I never do Starbucks, but I'm guilty of having full satellite TV and other niceties.
It's all relative to your income, really. My sister and BIL run a very successful business, and would have no real problem spending $20K on a hobby. I live a bit more modestly.
There was an issue with my insurance a while back where I thought my gear backpack had disappeared (turned out my mom grabbed it) and I was going to have to make a claim. A couple of my friends were there and heard me saying that there was about $4000 worth of gear in that bag, and they just about flipped. Yet one of them has a $45K truck with $15K invested in modifying it...all of which he's making payments on, with interest. My gear is paid for.