Tree House Twin-Over-Twin Bunk Bed
Asking $900 (new at $2,599 plus tax), and I will add two mattresses—one of which is waterproof.

https://www.potterybarnkids.com/products/tree-house-bunk-twin/?catalogId=10&sku=6158194&cm_ven=PLA&cm_cat=Google&cm_pla=Furniture%20%3E%20Bunk%20Beds%20%26%20Lofts&cm_ite=6158194_14728146703_aud-944520938055:pla-327533561682&gad_source=1&gad_campaignid=14728146703&gbraid=0AAAAADqwyxxT7s73m3f0abLdf_sml-v8d&gclid=CjwKCAjw6s7CBhACEiwAuHQcksU7MLqkAAbx92DzfSuxxmftAqCSa98g89biOIckcM8sR0iPpTgY5xoC3tQQAvD_BwE