Actually its very good lens and for a kit lens is pretty sharp, remember zoom lenses wont be as sharp as prime lens .
These 18 -55 mm kit lenses are available at Amazon for a reasonable price new , so much better than saving a litte bit by buying second hand.
Remember if its only saving a small amount on that particular lens as its not a big value lens new , its often much better to buy new in the first place . And you get full warranty and any problems return is met by Amazon.
If the lens was something like a nikon 70- 200mm 2.8 then buying used makes more sense.
Hope this helps .
Sent from my SM-T310 using Tapatalk