To the untrained eye, the smart repair type people to a good enough job, but to be honest all they will do is give it a quick rub down and blow some (quite possibly miss matched) paint at it.
My Mrs recently caught the rear bumper of her car on something, drove away and put a 8" split in it. I have taken it to a mates body shop (who is spot on) and he has quoted me £120 to plastic weld, repair and paint the bumper.
£80 to me sounds like alot of money for a quick job on the side of the road. I would rather pay a bit more and have the job done right.