Selling bikes for a friend, no idea what to price them at

I’m selling some bikes for a friend that recently moved and doesn’t have room for them anymore. They were purchased around 10 years ago, were well maintained and have been hung in a garage the past 5ish or so years. They told me they were decently expensive when they purchased them and used to be into riding pretty frequently at the time.

I have zero idea about anything bike related, I just know the model names. What else’s determines the value from the components?

TLDR: I’m selling some old ish bikes and have no idea what to price them at. They’re fully functioning but just haven’t been used in a long time. Trek Madone 5.5 and Cannondale Synapse. Pictures attached.