I would say around $200-$300 in repairs for the ignition cylinder replacement
BUT let's not get ahead of ourselves.
How about we try another key first? Maybe it's the key itself. If it is, then your problem is replacing the upper key fob and programming it at the dealership. This will have to be ordered and costs $60, as I previously stated.
Not working? Try some lubricant. There are three listed in the replies that are cheap and readily available.
So before we start going crazy, lets not make a mess out of a possible $5 fix, no? If its a 2011 beetle I doubt it needs all the locks changed if its one problematic thing going on.
And, breathe.