Shy, how can you quantify what is, ooh I'll risk saying it - reasonable - if you don't know what (if?) costs they incurred?
Looking at the planning application summary, they seem to have had a healthy number of consulting organisations (roads, environment, airspace, yada yada) to support the application.
I doubt it was a zero-cost/zero-effort process, and from the pics, they have at least spent a little bit of wedge on actual facilities.
I don't know market conditions in the area, but what is globally accepted, is anyone that calls themselves a consultant in a specialist area does not come cheap.
All this for what is quite an upmarket location where you're in for 35+ squid for a cocktail and a chicken skewer, so it comes with the territory, I suppose.