I just wanted to say that compared to the amounts many amateurs (including myself) spend on telescopes, eyepieces and imaging gear a basic roll-off obs is actually very cheap and simple to build.
Here is a link to a page I did to show the construction of my first obs:
http://titirangiobservatory.com/obse...struction.html
This is a very basic project, I purchased a kitset garden shed and converted the standard roof into a roll-off version. It took 9 days to complete (= 4.5 weekends), everything included from beginning to end - note the dates under the photos. Before I started I actually thought it was going to be much more difficult than it turned out to be, and I had really great fun along the way.
I have since moved house, and that meant I had to build yet another obs...!

This time I made it a bit more flash which I might upload some pics of some day. But that first obs served me very well and I just wanted to let you guys know for a bit of inspiration.
So, provided you have a backyard and of course provided your other half etc. agrees then an observatory is definitely not out of reach if you have a few basic handyman skills.
I hope you guys all get an obs some day soon - with the great imaging talents displayed here on the forums you definitely all deserve the best housing for your gear