I don't think you'd have any issues with safety with the cheaper ones.

I think the biggest thing is comfort. I had ones very similar to the ones you linked and I just couldn't get comfortable on them, though YMMV.

I got a bike fitting and he recommended these: https://www.amazon.com/Profile-Designs-T3-Aluminum-Aerobar/dp/B01KGAUB0W?keywords=aero+bars&qid=1535808207&sr=8-6&ref=mp_s_a_1_6

Even though they're much more expensive, they were much more usable for me because I could settle into a comfortable position.

As others have mentioned since the distance is short the benefit is debatable. I'd also check out the course profile. If you have a lot of climbing to do or very windy sections, you might not have enough time in the aero position to make it worth it.

HTH