What I would do is lay down some carpet squares along the floor where the wall will go. This will be to protect the flooring. Now, build out of two by fours a full partition wall. Space the studs two foot centers. drywall both sides as usual. Before rocking it, screw several screws fastening the wall to the floor, ceiling, and walls. Install the rock.
When leaving, take off the rock and unscrew the screws and dismantle the wall. You might have to do some spackling of the screw holes, but that is it.
This wall should not cost more than $75. installing a door will be more of course.