Do You Tell Others How Much You Have Invested in Your System?

I don't mind sharing that information, depending on who's asking.

I read once that you're considered an audiophile when your system costs more than your car, so when I bought my recent car (which city a little more than my system) I had to upgrade my system :-)

If anyone comments about it being a "waste of money," I really don't give a damn. It's my passion. 

Not enough yet. 
 

I always preface "I didn’t pay retail" when asked, but then I tell them what my system typically retails for.

And close with... "Don’t tell my wife".

Now if my wife asks, I tell her "less then your personal trainer", but only referring to my headphone amp.

I keep it on a spreadsheet so I remember what I paid (and the current list price) in case I didn't get a receipt. and so I know it if I end up selling it or trading it in. I don't keep track of stuff I've gotten rid of and how that "investment" performed. It holds its value better than clothes or furniture, unlike records which sometimes go up, so in my mind it almost justifies it. I don't keep what I paid for the records on a spreadsheet though I have a pretty good idea. All in all, it is WAY less than what people waste on golf, and time more enjoyably spent.

If anyone asks, I will tell them. Usually it's about a specific component or accessory. They rarely do.