Many credit card companies and collection agencies are willing to negotiate down the amounts for a lump sum payment, something you may want to keep in mind. But, when you make small payments, they just keep bleeding you dry.
Call them for a settlement amount. If they have reported you delinquent then they really have very little leverage. Make sure any agreement you make you get in writing first, before making any payments. They will pressure you, but make sure that letter is in your hand before dealing with the company.