There are also huge differences in the tax treatment of cubicles vs. walls, which can have a non-trivial impact on the decision making if it's an office of any size. Generally (and IANATL) cubicles and movable walls can be considered office furniture, whereas walls and doors are structural improvements - and those things have very different depreciation rates and benefits.
If you depreciate them, you have to either dispose of them at some point, or sell them at a loss (and you can only depreciate the loss). Over time it could cost more than walls, or have an extremely long depreciation schedule.
