Checking patient at home

A sheikh invites a doctor to check a patient at home, but the real motive becomes clear once they arrive.

Ek sheikh doctor k pass gaya or bola
k ghar ja ker mareez check karnay k kitnay pesay logay?
Doctor:300 rs.
Sheikh:chlain doctor sahab.
Ghar puhanchay to docor ne pocha k mareez kahan hai?
Sheikh: mareez koi nahi hai,
Taxi wala 500 mang raha tha