I have a 04 fiat doblo cargo 1.3 multijet, local fiat dealership have quoted £80 for an oil and filter change using selina oil which I think is 3 litres.
Fair price?

that sounds ok for a Fiat dealer.
I think you can get what they call a 'low mileage service' for about £170.

sounds ok for fiat dealer.

but almost any other garage will change your oil and filter and use half decent oil for about half that.

Had a customer bring her car in last week, and brought with her invoice for services, FULL service plus brake pads £95. Unfortunately the plonker who did it did not itemise the parts used, did not give part numbers etc, did not charge VAT or supply a VAT number. Blown warranty. Obviously he didnt reset any service counter either. A stamp in a book and a dodgy invoice does not a service history make.