The fact that the case has been filed in small claims court does not prevent you from consulting an attorney. If you cannot afford and attorney (perhaps you fear that the legal fee will be more than the man's claim), you can seek free or low cost legal advice through a local legal aid service. I have put a link to ProBono.net. Contact them and ask for a telephone conference. If they cannot provide services for you, ask them to refer you to a local resource that can.
You can try hiring defense counsel to help you. But ultimately you are responsible for the damages you caused. If the estimate for repairs seems too high, you can request the other guy take the car to a machanic of your choosing. But this late in the game he may not be willing to work with you. Sorry I don't have better news.
If you have insurance, you should have turned this over to them to handle. It sounds like you already went to court, and the judge awarded the other side more than they had offered to accept before the hearing. You chose to roll the dice and apparently lost. You can appeal the judgment. Make sure you do it within the time permitted, and if you have ins, get ahold of them immediately.
See other answer.
You might need to take the photos to a body shop and try to get your own estimate to give the judge. That's your best bet.
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