A person asks for an item or service, and is told that if they want 2, it'll be free and it would be much faster. The person did not have any medical disorder, nor were they asking for a task to be done to one of their possessions. What did they ask for?
The person selling the item or service was clearly joking. Nobody would actually ask for 2 of these, since it would defeat the whole purpose.
Tremendous hint (Will be added if nobody figures it out after a day or so):
To be added later