"Almost 10 years old. In fair shape. Needs a little paint. Must pick up - you will need more than one person to haul. Excellent for back yard or for a preschool."
I'm no photographer, but I do have one small suggestion. If you really want the preschool angle of your sales pitch to work, try taking the picture of your dilapidated playhouse during daylight hours. It will go a long way toward making it look less like it's inhabited by a play Blair Witch waiting to cut out the play tongues of small children and leave them for dead in the play wilderness.