Originally Posted by
cyccommute
It would depend on the age of the 520. For several years, Trek was outfitting the 520 with road bike style gearing which is way too high for touring. In more recent years they have been smarter about the drivetrain specification and have a more tour friendly drive train. The bad years are prior to 2009 but after 2002(ish). But $1100 for a model older than 2009 is too much. It's almost too much for a 2009 model.
Cyccommute, while I have much respect for your experience I have to take issue with what you've posted here. There are no bad years for Trek 520s. Trek finally reduced the gearing few years ago. The controversy being they didn't get it right. Still, those bikes with the reduced gearing aren't bad bikes, nor are the higher geared bikes that came before. That said, hundreds, if not thousands of Trek 520s have crossed the United States using standard out of the box road bike gearing. The higher gearing is an issue for some folks, not for others. For those who want to reduce the gearing, they can customize the gearing to whatever suits them, and do this relatively inexpensively. They can hand pick the components that are the best match rather than rely on an engineer's best guess for the mass market.
I agree that $1100 is to much for a used 520. A new 520 can be had for that amount, maybe even a few dollars less. Unless it's new in the box or has some expensive aftermarket parts included I'd offer under a $1000, way under - $700 -$800 for a almost new to $500- $600 for anything else.