Yeah, I didn't think too much of the extra $50 either.
But, I wouldn't let it keep me away from the Nationals. I went to the Open Nat's last year and had a great time. It's a great place to learn & it's a lot of fun. Considering, the travel & lodging costs, an extra $50 isn't that much.
Then again, I was lucky enough to have won an Open slot and was able to get a Limited slot through my Section Coordinator.
I can understand choosing not to go because of principles. But, then again you'll pass up a good learning opportunity.
Good luck on your decision!