I bought a brand new one and it's fantastic. The used market for premium chairs in my remote part of the country is non-existent. I certainly would have bought a second hand one since they are so well built.
+1 for this. I bought my Herman Miller Aeron new almost 20 years ago now and I still love it & use it every day. Immediately fixed some (very mild) back trouble I was having.
It probably won't fit the Shopify budget, it's super expensive. But having the same chair used in recording studios and is officially a work of art in the Museum of Modern Art [1] still makes me smile every day I go to sit down to work.
Yeah, I bought the executive Aeron because I couldn't stand so much plastic and it cost an eye watering £1200.
But I'd spent £300 on a chair before it that didn't last three months, wasn't as adjustable or comfortable, I couldn't get a refund on and for which there are no spares on eBay. 10 years in it's looking like a great buy.
Also not OP and I also have a Mirra 2. There is a school of thought that as the Aeron is a design classic they can't really iterate on it. The Mirra has been great for me.
Not OP but I have a Mirra 2, I liked it better than the Aeron or Embody. I do really suggest you go someplace where you can try it out, also the various sizes. I bought refurb, don't remember price.
But even when bought new, something that gets used so much everyday is worth the price.