Small scratches on the front element usually have little visible effect on normal images. In most cases they do not show up as sharp marks in photos because they are far out of focus, especially when shooting wide open.

The most likely downside is a slight loss of contrast and increased flare/veiling glare, particularly in strong backlight or when bright light sources are in or near the frame. Wide-open shooting tends to blur the scratch effects more, though flare can still be more noticeable.

The impact is generally less obvious at longer focus distances. Minor front-element damage is often less harmful than people expect.

If you buy it, test it carefully with bright light in the scene and compare contrast and flare behavior. Cosmetic wear may be acceptable for hobby use if the discount is worthwhile, but avoid it if you often shoot into the light or want maximum contrast.