I use the replacement ikea bases, the wheels are crap but I replace them with Amazon skate wheels, I have 2 and they are a couple years old. More on reddit.com

I think you will do better replacing the chair. This looks very inexpensive in terms of construction, so you will not get many years out of it in my opinion. Reach out to an independent office furniture dealer in your area. I am a used office furniture guy and recommend starting with someone like me. We will have better quality used chairs from major manufacturers and also would have access to ok new furniture like what you show (usually for less money than a big corporate seller like in your link) Not my recommendation, but if you want to try and fix your chair. contact the manufacture or the store you got it from. They may have a replacement program you are covered by. If not, I start at the wonderfully names Oddles of parts plus to locate the hard to find pieces. If not them, you can look to ebay, but comunicate with the sellers and make sure what they sell is exactly what you need. Last, if it is the mesh, you may be able to have it re-sewn in place if you have an upholstery person or perhaps a tailor who has the tools to patch your mesh. More on reddit.com

Steelcase or Hayworth More on reddit.com

Any luck finding replacements? More on reddit.com