Could always try seeing what a highly regarded/recommended auto upholsterer could do and how much they would charge to give you the same outcome whilst also giving you more choice options on materials / colours etc.
Edge Automotive
Plush
MJ Interiors
If that would be a cheaper option and something that would interest you, i'm sure other members on the forum would help you with recommendations in your area for car / auto upholsterers then you can find out costs etc and compare to the figure (£350+) mentioned above...