Transmission Fluid Change

I recently had an oil change performed on my car and the workers there mentioned that I needed to have my transmission fluid changed as well and wanted to charge me for it. At the time, I declined.

Were they just feeding me a line to get me to spend more money at their shop or do I really need to consider changing the fluid? Is there any way I can tell for myself that it does in fact need to be changed?

Car has about 85,000 miles on it and to my knowledge has never had the transmission fluid changed.

Thanks in advance.
Steve Hi: At 85K miles on your vehicle Car Repair Talk's forum.