This is a decision you would have to make.
Since this debt was occurred while you were married, the debt could be paid by the both of you, your ex spouse or you alone. The credit card company would not care which of you paid the debt, nor the agreement you and your ex spouse make between the two of you. Both of you are listed on the credit card account. The both of you signed for the credit card account.
If this credit card debt is bought by a credit collection agency, you are in a different situation.
You would need to look up the laws in your state of unsecured debts. In most cases this debt would no longer be listed on your credit report in 2-4 years depending on the state laws of your state concerning unsecured debt. credit cards are considered unsecured debt.
If you decide to make a deal with the credit card company to pay the debt, you would be making a deal to pay the entire credit card debt,not an agreed amount you and your ex spouse has agreed upon.
In making a deal with the credit card company, you would not longer be required to pay interest on this credit card debt. You would be required to pay the current balance of the credit card debt.
If might be that you would file for a bankruptcy to protect your current income and future income from being in jeopardy. You might want to consult with a local attorney to find out your options, in this matter.
This bankruptcy would appear on your credit for several years. This would prevent you from the purchase of a property for 24-36 months if you would need to apply for a mortgage loan.
You would have to reestablish your credit and have credit score required of your mortgage lender.
Since you would not be able to purchase a property for 24-36 months this would allow you to save for t he purchase of a property.
Also your income would not be in jeopardy. as the bankruptcy would eliminate any and all debt you have incurred.
It might be that you are able to find a solution to your situation by speaking with a financial expert in your area. There might be a means of you to avoid paying less or eliminating your debt. In most instances if you are able to pay less or no debt to debt holders this is akin to filing for bankruptcy and would appear so on your credit report.
If this is your option you might as well file for bankruptcy.
You would need to speak with t he proper individuals that would be able to assist you in making your decision and what would be to your best interest financially.
No one on this forum would be able to give you correct or legal advise, we have no idea as to your financial situation of the laws of your state.
I hope this has been of some benefit to you, good luck.