Help on buying a used bike please give advice

[Lukem]

Is the diamondback 2017 mission 1 bike worth 850 dollars? I have a chance to buy one today?

 

[Cycleops]

Depends on the condition and how worn or not the components might be.

 

[durianrider]

Depends if it fits you. Drop the fork out and inspect for any cracks. Do the same with the bars. Best to buy new if you don't know what to look for safety wise.