I hear you on that... I've not had my scopes out properly in quite a while...
I too have thought about the idea of 4 scopes/4 cams... The problem being, How would the computer handle running 4 SBIG cameras all at once? I suppose if you're going 4x150mm AP's on a paramount, the Obs PC is going to be no slouch!!
I do what you're doing in my head all the time... Im constantly wondering what I dont use often enough to justify having, how much I'd get for it and what marvelous astronomy gear I could afford with said money!
I even considered recently my 52" HD LCD TV, for a good triplet APO or a G11 mount
What can I say.. Im an Astrotoy Addict!