I feel the locking brackets should be included with the rack. If not included, then they should be more around 20 or 30 dollars. 70 dollars is a stretch. You still need to use half the parts of the original brackets that are included. The locking bracket is just a cap that covers the holes. It looks like it would cost a few bucks to manufacture. I did want the locks with my rack, so I did end up paying the price for them and they do the trick, but for what you get they are pretty expensive.
2013 Subaru XV Crosstrek