I think the answer is a job and a bank account. If you have a bank account you can get a debit card and use it for online purchases. This is what I do. I have no credit cards.
Chores are a pain for you but while youre doing them with gritted teeth, REMEMBER you get more by sucking than you do by biting....
Good luck, Red!
We're all pulling for you!
Do you have a local fish club? We have a couple kids that come with their parents and everyone learns a lot. If you can take your parents maybe they could talk to people who have been in the hobby for some time. Many of the members of my local club are much older, have lived through many technological changes in fish keeping and one of their fears is the hobby is dying out because young people are not coming to meetings. I'm sure they would be thrilled to have you and your parents join them. You might even be able to get free or cheap plants, equipment, and fish.
...How long before you turn 18 and can get your own card?
Solution: Buy one of those prepaid visa gift cards. You can use them online...
Go to walmart and get one of those Visa preload money cards and use it online, thats what my gf's family did for her for christmas cause they didnt know what to get her.
That would be your easiest option. ORRRRR
This is what I would do when I was younger, if I wanted something, I would wait til my parents fell asleep, snab my moms credit card, order it, and put it back with an envelop laying on her purse saying "mom, ordered such and such, used your wamu card" and put the money in the envelope.
Yeah she was mad for a day, but at least I got what I ordered and once she realized that it was MY money to spend however I chose. She quit bothering me, she just checked to make sure what I was ordering was what I was paying her back with.
Circumventing your parents and their "ways" is asking for trouble. If you have shown fiscal responsibility, openly talk to them about your own checking account and how it will teach you better on how to handle and budget your money. (If you walk around broke all the time then you do need to learn.) If they refuse to accept the "new ways", arguments will only make them dig in deeper.
If your grades are up, go to the library and check out books on planted tanks or aquariums and read them. Share some of these readings with your parents. Who knows, if it comes from a book maybe they will be more open to reason. For online information, go to University of Fla to support your position. Coming from a University may help.
Good luck!