(500ml for the price of 250ml) All Redex fuel treatments are 100% extra free:
**Petrol injector cleaner** Shelf Label price £3.63 BUT scans at £3.17!!!
Petrol cleaner (for carbs) Label price £3.17 (dunno what it scans at though)
Diesel Cleaner Label Price £3.62 (dunno what it scans at though)
The SRP for 500ml Injector cleaner is £7.49 at most retailers.
I bought mine at the forecourt but i'm sure the prices would be same instore?