Looking for a rat cage online!?

I am looking for a "Grotto" style cage. A bookshelf or something similar that has been crafted into a small animal cage. I am looking for a cage that is affordable. I am not looking for a cage like Martin's Cages. I am looking for any cage that has solid bottomed floors. If anyone has a link for me as to where I can purchase such a cage, please let me know!!!! TYSM