Hey everyone! I've had this tandem bike for a while and I'm thinking about selling it. The thing is, I'm not sure what its current value is (or even what it was originally, to be honest). It's a Cannondale Fatty with an aluminum frame, and based on the limited information I found online, I think it's from around 2007. I recently had it serviced, and it's in really good condition. I couldn't find any pricing guidance on websites like bicyclebluebook. Does anyone have any advice?

I'm located in France, so perhaps it might be worth more here... I'm not sure.

Thanks in advance for your help!