First things first: has your property done mini models before? Do you have anything left over from those? It would be nice if you had a shower curtain and rings from a previous one. However, this is my personal opinion - I do not like cheap-looking accessories in my mini models, so for me, the property should invest in some really thick towels and a beautiful shower curtain with classic rings on a curved shower rod for the bathroom.
Dollar Store: Concentrate on kitchen and bath items that will stay with unit, possibly.
* Dishtowel
* Cutting Board
* Strainer or Bowl or large cup into which you place snack items
* Soaps
* Roll of Paper Towels
* Long handled brush laid on top of a folded towel on the side of tub
* Hangers in the master bedroom closet tied with bows
How creative are you? Can you cut out silhouettes of a dog and cat? If so, do this and place in a corner (standing up) with two food dishes in front of them on top of a rag rug (if your community is pet friendly.) Oftentimes, I bring items from my design business to use, too, and I have swapped items with furniture stores, too for short periods of time (like for a special open house weekend showings)for staging purposes. I would also blow up large cutouts of bubble words to label special features of your apartment mini model. Another thing I have started doing too, is using magnetic chalkboards in the kitchens and writing cool quotes about home on them. With $20 there is not much room for going overboard, is there?
I am sure I am missing some other easy to do things ..... does this help? Maybe some others have other suggestions!