As a comparison, I was recently offered a Mitsubishi service plan for my Mitsubishi Shogun SG3 for 3 years at a price of £975.00 for all parts and labour irrespective of the mileage I covered or the amount of services required. (great deal for high mileage users)
Also, I was recently offered a similar plan for my Nissan R35 GT-R TP at a price of £1495.00.
Both the above vehicles are fairly new and appear to be competitive quotations and might appeal to the layman.
However I can service both these vehicles myself at a fraction of the cost, and still retain the manufacturer's warranty.
Rather than enter into a service contact I would advise that you approach an informed, trustworthy, recommended indy and obtain/negotiate servicing prices from them.
Alex.