@Maybeebebe
I'll caveat this with I don't work in NHS procurement, but another complex public organisation and collaborate with others. The detail is different but principles are there.
Dr tells me to get paracetamol
2 options
Option 1: I get from Chemist
dr writes a script (in same appt where they tell me I need it)
Storage
people to put on shelves
People to dispense
people to pay
Cost to me either 8.99 (or whatever it is now) or free if eligible
How much does this cost the NHS?
Unsure on exact figures, but factor in staff time, systems/software/licenses, training, leases, building maintenance, utilities, hardware for all aspects including procuring the contract to supply the item, managing that contract, prescribing, the admin behind it all, processing of data, the pharmacy and pharmacy staff too.
Option 2: I get from Tesco
dr has told me to get it
storage
people to put on shelves
People to dispense Checkout 'checks' age/amount
people to pay
cost to me £0.50
How much does this cost tesco?
That's a bit different as Tesco will procure differently and the cost is intertwined with their other operational costs. At 50p a box Tesco are making a profit where the NHS are not.
Also, the NHS is saving the cost in terms of prescribing the over the counter medication to you (and the checkout staff are paid significantly less than the doctor and pharmacist)
Again very simplified and generalised. Obviously there isn't staff and software specifically for paracetamol, but there is a significant saving to be made from stopping the prescribing of over the counter medicines.