How to I add Fixed price Charges in my Request Ticket

How to I add Fixed price Charges in my Request Ticket

My Customer Service team opened a Ticket on behalf of a Requester who called in with a Slow Computer Issue, 
While he was working for a half hour to resolve the issue, he saw that he needs a new Network cable.

Now My customer service Rep logged a Half Hour of Billable time, but he also wants to log that he sold him a new Network cable so it should be billed accordingly.
How do we go about this?
                New to ADManager Plus?

                  New to ADSelfService Plus?