I don't think the number is correct.
Just to start of with some clarity, the cost to the patient of all of these services is nil. This poster is advertising the cost to the National Health Service of various forms of treatment. Presumably, the intent is to make users of these services aware of how much they are costing the health service.
Most of these figures appear to be taken from studies performed periodically on the usage of NHS services. One is easy to find online - Reference Costs 2012 - 2013 - gov.uk
That report contains a summary, which has similar figures to the image in this question (possibly adjusted for local variation, or possibly average over the report year and previous year).
Some headline statistics from the 2012-13 data12 (with comparisons against 2011- 12) are as follows:
• 2012-13 reference costs cover £55.2 billion of NHS expenditure, an increase of £1.7 billion (3.2%) over £53.4 billion in 2011-12
• This represents 54% of £102.6 billion13 NHS revenue expenditure in 2012-13
• 5.6 million data items were submitted by 244 NHS trusts and NHS foundation trusts
• Detailed costs were provided for 2,100 treatments or procedures covering over 15 million FCEs within admitted patient care alone
• The average cost of a day case is £693 (£682)
• The average cost of an elective inpatient stay excluding excess bed days is £3,366 (£3,215)
• The average cost of a non-elective inpatient short and long stay combined excluding excess bed days is £1,489 (£1,436)
• The average cost of an excess bed day is £273 (£264)
• The average cost of an outpatient attendance is £108 (£106)
• The average cost of an A&E attendance is £114 (£108).
I have highlighted the specific item in the above summary which seems to answer this question in the affirmative.