Am I wrong for feeling this way?

The crux of my argument is this whole "equal oppurtunity bit". Simply stating "I need to save more money, so I can move out" will not even phase him in any logical sense. To be honest my mother thinks I shouldn't be paying rent at all, my girlfriend also not paying rent herself caused a previous engagement about this between them, not me, because at the time, I felt like I should be.

But after the recent events, I feel as though I'm more on the lines being bolted down because I can afford it. So although, yes in majority of negotiations, bringing a foreign entity into it "but her parents let her!", would normally be a bad call, I feel as though the crux of this ticket situation proves my point. Why stress fiscal responsibility on me, especially in this economy when it's handicapping me, while the idea of responsbility hasn't even been whispered, let alone fiscal?

If you're dead set on presenting it as "Why do I have to pay rent while sis doesn't even have to pay her traffic tickets?", go ahead. You know your parents better than any of us. If you think that will work, good luck.

In my opinion, they will simply say, "Because she's not 18 yet. We paid all your expenses when you were 17, too."
Now, you know, and they probably know too, that nothing will change when she turns 18. Doesn't matter. As long as it hasn't happened yet, they can use this answer.

Also, if moving out is not a goal they want you working towards, try something else. Perhaps you're saving up for an advanced degree or something of the sort, education that can improve your earning prospects?