I was making a right turn last week and almost got hit by some guy trying to take a left turn all the way over into my lane.
And that's a situation where the law makes sense. The law doesn't make sense where you're not at a 4-way stop, like exiting off the interstate in the OP's situation. In that instance, it doesn't matter which lane you turn into because there's no oncoming traffic.
I received a nearly identical bullshit ticket just a few months ago when turning right at a highway exit. I turned into the inner lane because my very next turn (less than half a block) was to turn left from the inner lane into a neighborhood. I tried to explain this to the cop - he wrote me the ticket anyway. This is why I strongly dislike cops. It's all well and good when they're actually "serving and protecting," but they too often engage in nothing more than writing up bullshit tickets to raise revenue for their new SWAT gear.
But in answer to the OP, pay the fine. You'll actually end up paying more money in adminsitrative fees (yes, you have to actually pay more money to get your "trial") than if you just pay the ticket, and you're going to lose except in the rare instance where the ticket is dismissed because the cop doesn't show up.
Besides, if you believe in karma, there's a good liklihood that cop will develop ass cancer in the near future for the screwjob he gave you. So take solace in that.