Hard to say really, no picture, no description, no anything such as a model....
Lets assume that it is 5 years old and used so that takes off 50% right away (from original purchase value) now lets say it was $180 originally that would take it down to $90 at most and lets take another 20% off that for likely excessive use...? That would make it a $72 bike and you have been offered $120.....TAKE IT!
Lets assume that it is 5 years old and used so that takes off 50% right away (from original purchase value) now lets say it was $180 originally that would take it down to $90 at most and lets take another 20% off that for likely excessive use...? That would make it a $72 bike and you have been offered $120.....TAKE IT!