In search of choir risers

Hello, My son's school is in need of additional choir risers. If anyone has a lead on reasonably-priced, used, folding choir risers, please let me know. Wenger brand preferred. Alternatively, if you know of a source from which the school could rent or borrow a riser, that would also be appreciated. Although the school needs to purchase additional risers for long-term use, the immediate need is for the school's upcoming holiday concert. Thank you, Deadra Keener