Yes, that is too much money for a very minor infraction at a time of low traffic. Cops certainly do have leeway but California needs money. If it’s not too late, go to traffic court and explain the circumstances; you might get a break from the judge unless he has been instructed to not be lenient if CA needs the money. I’d call it cruel and unusual punishment to take a week’s pay for that. The cop could have given you a warning for being a little confused in your interpretation of the bicycle lane users rights. Aren’t you supposed to stay out of the bicycle lane as much as possible with your car?
A few years ago I was out for a long walk and came across a couple of cops who were monitoring speeds in a 35 zone and were letting people by at 15 over. I asked why; was told that traffic was light and so 15 over was safe enough. Cops have discretion and so traffic laws are not absolute.