Actually, dunno about the US, but where I live you _can_ prepare for a legal battle too. E.g., I have basically a lawyer insurance, in case I end up needing one.
Second, do some basic maths, mate. If you were going to train two hours a day for when you need to duel, the same amount of energy devoted to saving money for a legal duel will put you quite far ahead too.
The RIAA is distasteful, but, sorry, they _don't_ take your money before you go to trial. They try to scare you into settling _instead_ of going to trial. Sorry, but, that's a whole different thing. If you want to fight instead, you start with exactly as much money as you had.
And there _have_ been people who've won against the RIAA. Sometimes through equally underhanded PR tactics. E.g., the mother who went the "OMG they're suing my 6 year old daugher" bullshit route... although the address had been traced to the mother, not to the daughter.
Of course, there have been dumbasses who've lost too. Like the retard who tried to destroy the data and give the court a different hard drive.
Sorry, the system isn't perfect, but it seems to me like it still works better than the dick-waving contests of yore.
Even in your example, by ye goode olde laws you'd _still_ be screwed. Someone rich or with rich relatives, would hire a veteran as their champion to fight you. And history has plenty of examples like that, where the "duel" was little more than legalized paid assassination.
E.g., if you think that because you're a macho man, you could intimidate your wife into not wanting a divorce any more... well, that gives me an idea of why she wanted a divorce in a first place, sorry. But I digress. Well, her millionaire aunt would hire a thug to beat you up physically, if that's how justice went and that's the kind of trial you want, instead of hiring a lawyer. It's still not an improvement.