What are the results of trademark infringement?

Hi, I am from New York and I was selling Nike Air Force 1 on ebay and one day someone showed up with some letter from the lawyers saying I am selling "offending products" under the Nike Trademark/Logo I had no idea they were "offending products" now the lawyers are offering to settle this matter but wants this large sum of cash from me I am not able to pay this sum because I am still in school and I am unemployed. If they do sue me what can happen? Let say the court does rule an amount for damages but I cant afford to pay it then what? Please advise.