Is there a better (meaning cheaper but ergonomically excellent) chair to buy for my home office?
They are great chairs, but there are also some really good ergonomic office chairs at reasonable prices. Here's a good site that has some info about how to choose a good chair and they also have good prices. Hope that helps
Probably, but shop around. I found drastically different prices from site to site.
I actually find Aeron chairs to be uncomfortable, not enough support. And the company I used to work at developed a similar chair but more affordable. Herman Miller wasn't exactly pleased since our company also supplied components for them. Personally I think you can find a lot more comfortable chairs out there that are more reasonably priced at places like Staples or Office Depot.