While I am not a Nikon user, I have used prime and zoom lenses made by other manufacturers. Some lenses do require a heavier touch, but the focus ring should still be operable with just thumb and index finger. There is no particular association with being a prime or zoom lens and having "stiff" control rings.

Since you tried the lens in-store, you should have been able to try different copies of the same and other lenses to verify what the salesperson told you. If the lens was previously owned, perhaps this is the reason the original owner no longer wants it. Consider listening to your Spidey sense in the future.

If function of focus ring does not appear to improve with heavy use over the next few days, I would return it, as Horitsu also suggests. Find a rally, festival, demonstration, or other event and take as many photos as you can. The lens itself is unlikely to change, but with increased familiarity, you will be better able to judge whether this quirk is acceptable to you.

Here are some factors that could affect lens operation. Many do not apply to your lens.

• Broken? Is there any "grinding" while operating the lens? Do there appear to be any loose components within the lens? Do the AF motor and other lens features work as expected? Do other copies of the lens function similarly?

• Needs to be cleaned, lubricated, and adjusted (CLA)? This should not be the case for a brand new lens.

• Requires the AF motor to be disengaged? This does not appear to be the case with your lens.

• Weather sealed? This does not appear to be the case with your lens.