Stupid question. Please humour me 
Can you get... fake oil? Reason I ask is that I've found a shop on Ebay selling a top brand, high quality oil for about 40% less than Opieoils etc want for the same oil. Could it be dodgy? They certainly look reputable.
Is there anything to be worried about when buying oil like this? The price just seems too good to be true? It'll come to £54 including post for 8 litres. OpieOils want £78..

Can you get... fake oil? Reason I ask is that I've found a shop on Ebay selling a top brand, high quality oil for about 40% less than Opieoils etc want for the same oil. Could it be dodgy? They certainly look reputable.
Is there anything to be worried about when buying oil like this? The price just seems too good to be true? It'll come to £54 including post for 8 litres. OpieOils want £78..