You can probably find one on eBay and Etsy too. I bought my CSW there.
I also have my wheel placed in a rabbit sized litter box where my hedgie does all her business. The wheel fits in there too so I just take it all out to clean it. She loves her Carolina storm wheel and they can be pretty reasonably priced on Etsy. She loves it and loves to run and it’s a bit more stable than the ones sold in pet stores I feel.