Second audio system in your house?

Oh, one more thing comes to mind- guitar players coin a phrase called "GAS" - or Guitar Acquisition Syndrome.  This can result in something quite similar to too many audio components.  A doctor i knew had over 40 Fender Stratocasters and Telecasters. Along with over 40 guitar cases, and innumerable sets of strings, stands, cables, amps, sound processors, and other accessories.  So we're not "entirely" alone in taking a hobby too far.
(as long as we don't forget about the millions of people who don't get enough to eat... here in the U.S.A....)

3 systems.  A Fi Audio of NY-based one in the family room; a Kondo-based one, and a Concert Fidelity-based one.  They give me pleasure, and I have an understanding (read: great) wife of almost 28 years.  I keep the Fi Audio and Kondo equipment for many reasons, one of which they represent the crucial efforts of the designers that brought them to life.  I keep the CF equipment because of the performance excellence (to my ears).  Most components were purchased at good pre-loved or demo prices, so, substantial dollars invested but not totally whacked-out - all things considered.

 Oh man french_fries, you hit the nail on the head, I seem to take all my hobbies too far. Hifi in and of itself is a bit over the top for the general masses. For example, somehow I've aquired over a dozen fine tobacco pipes in the past 6 months. I suppose it's a bit of a personality disorder. 
 Well after reading all this it appears the magic number is 3, so I'm still clinically sane (if you don't count my car) and within reason. Hell I'm basically obligated to build another at this point. The problem is, I've always wanted to try out an all tube system, and maybe a killer headphone set-up, so I can see other systems off in the horizon. 
 

I'm another one with two systems.  I have a dedicated 2 channel system exclusively for vinyl.  VPI turntable, PrimaLuna tube pre-amp and a Cary c280 V12 power amp.  ....all second-hand gear!

I have a second rig in my home office for headphones.  I have a dedicated Oppo HA-1 DAC/headphone amp and a LCD-3 headphones.  ....lossless digital bliss.  

Look for some used equipment, however, buy something you like vs. a good deal.  You will end up changing equipment out to get what you really want.  I have a McIntosh 6600 integrated amp and ProAc speakers for the main listening room, a great sounding system.  If you can't spend more than $1,000, look for the used equipment.  I ended up with a third system in my office and spent too much $ 7,000, but I love it.  As mentioned from some of the other equipment lovers, you can't have too much gear.  The wife doesn't get it, that's ok.  Have fun, owing the equipment is the fun of it, especially, if it's great gear.  I call the audiophile experience the black hole for spending money, you can't take it with you so enjoy it.