It's free, a lots of mechanics tend to use Halford Advanced over big brand such as Snap-on, while they're not the ulimate tools to use, it easy to replace with no question asked.
I've replaced my bit dozens of time in the last 4 years without spending any money.
Fuck that, go Halford Advanced, they do lifetime warranty, so when I broke a bit, I send the whole thing back and get a new one.
Every time.