Related Clues:

• One receiving treatment
• Invalid without one, it's obvious
• Not quite prompt payment
• Willing to wait
• Sufferer prepared to wait
• Hot drink, half price
• (Entry) charge
• You must be this in the doctor's waiting room!
• I got involved in obvious case
• Long to insert ligature, one of interest to medics?
• One's placed in sort of leather case
• Investigator primarily looking into copyright case
• Charge for iron's expensive at first
• Payment to professional
• Job was open — one had to go in for it