Many things - I studied as an architect so I've spent some time there but I've also designed sets for rock music festivals, rock bands, television and theatre. I have been a university professor at two universities, spent about five years working at a software company, worked as a technical consultant to a computer animated cartoon, did thematic design for a casino and various other architecture and design related projects. A long time ago I wanted to be a musician until I realized that I wasn't that good and basically I'd starve to death eventually.
I'm 43 now and I've decided to stop working for the time being to focus on our children and life in general. I have some health issues that I need to focus on and my music hobby helps me with that. I may return to work one day but I doubt it. If I did I think I'd like to try something different anyway. I like variety in my career.
I've had three main systems in my life thus far.
The first was when I was a university student in the middle 80's and I think I had about $10k into it with a Maplenoll turntable as the front end.
The second was a simple digital front end with an integrated amp driving hybrid electrostats. This lasted from the mid 90's to about 2003 and it was about $12k.
After that I started building the system I have today which is finished (finished = no more major additions or alterations as I'm happy with it). It's a two channel system in a dedicated room and the list price would be somewhere around $265k although I've purchased a few pieces used and others have increased in price significantly as of late because of the US dollar so, the real value is more like $193k. It took seven years to get here but it was working in some capacity throughout the build.
I've loved all the systems and enjoyed them a great deal. I've collected a number of LP's although I try to keep it to around 3,000 recordings at a time. Another 800 or so on the computer (CD's and HRX files) and I'll have 20 reel-to-reel tapes from The Tape Project. I've never stopped to calculate the value of the music because to me it's like food. You've got to have it!