Comments about the service pricing being reasonable for the type of car are valid and I never would (or would advocate), cutting corners on servicing/maintenance, but actually the type of car being worked on is largely irrelevant.
The key consideration is (or should be) the parts cost and the actual work required. Considering that the Evora runs a Toyota Powertrain and has less work involved than certain Elise models then it would be reasonable to expect that the servicing cost in the same garage would be no higher. Less work should equal less cost.
Why for instance would a fluid change be any higher than for a VW/Merc/BMW etc within their networks?
Considering the price variations in the network, it says to me that the costs are being set around value of car and what the specific dealer feels they can get away with, rather than an assessment of the job. high value car = higher cost servicing.
nb - there is about a 30% cost discrepency in the Lotus dealer network between the lowest price and highest price dealer where I can find thier costs. Other service items are even more disparate, for example Geo at one dealer - £250 - another £120.