@timmyteo did you mean costParsed == 60 here? (the participant passes the challenge if they are able to alter the 60 value that is embedded in the html on the else branch)

@paul-ion The goal of this exercise is to "Find a way to renew the subscription without paying any money." This would likely be accomplished if the cost variable value is set to zero or a negative number in the form. The default value is 60.

There is some input validation in place with if(costParsed == 0), meaning that the likely first tamper choice of zero is protected against and will be rejected. But there is no validation for negative numbers. In the context of this vulnerability, there is no reason the form should accept negative numbers and we would expect them to be rejected. In order to pass the challenge, a negative number must be submitted.

Please let me know if the challenge makes sense. I am open to modifying any aspect if you think it would improve learning or understanding. Thanks for your feedback.