I have almost all of the $400+ star wars sets (and lotr, and star trek, ...), but relatively limited shelf space.

They only stay on the shelf for a couple years before I take it apart, rinse the dust off, sort it into ziplock bags, and add it to a box in the closet. Then I pick an old one I disassembled before, but hasn't been seen in awhile, or remember having fun building it, and spend a weekend or week building it again.

My favorite part is building them, so I get to enjoy doing that several times per set, often while having the corresponding movie on in the background.