If in fact you do owe the $2,300 and can afford to pay $50 a month, then it's probably not a bad deal. Your only other alternative is to participate the lawsuit which you will likely lose unless you have some valid defense, which will result in a judgment being entered against you by the court and then it would be up to the court to determine how much you should pay a monthly basis. If you do agree to pay the $50 a month, make sure that all of the terms are in writing including any provisions involving interest, late payments, penalties, etc. It would probably worthwhile meeting with a lawyer to go over any agreement before you sign it.
I agree with the prior response, but I'd also add that if this credit card debt is just one of many that have finally caught up with you in the court system, you may need to start thinking about other options. Agreeing to a payment plan won't help you if other debts will surface and collectors will start enforcing their rights - leaving you to juggle a number of judgments, liens and potential garnishments. If this is your only debt, $50 a month sounds like a good plan (although paying it off sooner is a better plan). If this is not your only debt, and this court case is a symptom of a larger problem that you don't mention, talk to a lawyer and start exploring some longer term solutions.
NO! Do not sign that form!
By signing that form you are agreeing to give the Plaintiff judgment in the full amount he is seeking, plus agreeing to give him statutory interest at 12% a year. You are also giving him the right to have a sheriff come to your home, seize your property, and garnish your wages. You can settle the debt without giving the Plaintiff judgment! Paying $50/month will barely cover the interest, and you will be paying them forever.
I would explore other options before granting them judgment. You may pay a little to consult with a lawyer, but it could save you thousands.