It's my experience in these kind of situations that those behaviors are very entrenched, and that it will be really hard for you to change them,... Your mother has developped a way of dealing with your sister that is unlikely to change in the near future.

Nevertheless, there are things that you can change and act upon. For instance, it's pointless to expect total fair and equal treatment from your mother, it's just her personnality. On the other hand, you probably can get more out of her by being more assertive.

For instance, make a deal with her that in order for you to get a job, you'll need to be able to drive, and that even though she does not plan to help you for college, she could help you to get your driving license, so that she does not NEED to support you later.

Also, don't get A grades for your mother, but for yourself, that's the only good reason to get them. Although you feel it's unfair, it's taken for granted that you get good grades, and so you get less "perceived" recognition for that. I always had excellent grades, was never congratulated for that, and did not expect it, because it was just "business as usual" for me.

Finally, you see yourself as being well behaved within your family. That's all fine, but please do that because you think it's the right thing to do, and not to get appreciation from your family, because otherwise you will get frustrated. You are not doing your family a favor, you are just behaving as you should, so don't expect anything special for that.

Don't allow what you perceive as injustice enbitter you and sore your relationship with your family. I have the hunch that your mother also loves you, but has different ways of expressing it than for your sister. Think about it, if you behave as a more frugal person, it's normal that people will think of ways of satisfying you other than stuffing you with game consoles, etc. It really seems that your mother thinks that supporting your trip to Japan was a wonderfull gift, and I basically agree with her. And your way of reducing it to "bare educational necessities" strikes me as quite unfair.

I'm not saying that there is no unfairness within your family, but maybe it would help you to take a step back and evaluate from another angle what's going on, and how you perceive things.