I use my desk as my workspace too, simply because the house I live in is too small to have it anywhere else, so I end up with paint all over my desk, and even some tan on the lower part of my keyboard where I had oversprayed with my airbrush
Part of the problem is indeed where to KEEP them all. Oh, and of course where to display them once they're built. The closet in my bedroom is literally packed full, both on the shelf and in the floor all the way up to the shelf, so a space of I think 2x2x15 packed to the brim, then I have a tower at the end of my desk that's also 2x2 but only about 7 ft high, then I have some on the desk, over by the TV, in the spare room closet, in the livin room tucked away.. so I literally can't go anywhere except the bathroom withint staring at a bunch of kits in boxes. I think I do feel guilt over having so many, and in a way even how I got them all. See, back like a year or two ago now, I was dating this girl and she HATED models, thought they were a waste of money and space, just "fancy toys", and we were trying to save money for a place so I sold all but my favorite 10 or so kits, and then just short of 8 months ago she left me for someone else, I guess she was tired of waiting to move out of her parents house and I ended up picking the hobby up to distract me from the hurt, especially since I didn't have a steady job at the time to help with that. In those 8 months I've built around 20 models, and built my collection up from the few I had left to the 500+ I have now (yeah I went nuts and spent everything prety much I had saved on models, lots of paint, and an xbox360 lol)
I do take time to do other things, lately I've been wrapped up playing Saints Row 2, and started collecting Manga again, and actually reading them as I get them. I think part of it though, in addition to constantly seeing all these models is I keep seeming to mess somthing up lately. The last two things I've tried to build got messed up. One was a Harley, I glued the hand grips on the wrong side, so they were upside down and it was very noticable, and I use the quick drying glue so I couldnt' get them both off, only one. And the other was a Yamaha Roadstar (similar style), and I dropped one of the long screws that holds the wheels on and well I can't find it no matter how hard I look.
I do have a variety, while I do have more cars than anything, I still have lots of aircraft, a few tanks, even a boat (which scares me.. the USS Constition.. a friend gave it to me years ago). I couldn't even begin to say how much I spent on all these kits, because honestly I havn't kept track, but probably more than $10,000, ranging from a few I got for 99 cents (even a couple I got free cuz of a really nice seller on ebay), all the way up to around $100 for the PL Enterprise NX-01 1/350 scale.
I really do wish I had somewhere to put them other than in here though. I wouldn't dare put them in the storage building we have now, unless I had a nice big steel container cuz it leaks, is so flimsy (plywood and a few beams) and just yeah, I wouldn't trust it with kits.
Triarius - I've never been one of those people who super details stuff, mostly because I'm just terrible at it. If some detail can be painted on, I can ussually do it unless its really small, but other than the damage/dirt detail I did to one dirt track racer I built, most things I build are OOB. I tried doing wiring once on a car engine, bought the wires and everything, but I just couldn't get even ONE to stay in place so I gave that idea up for now haha