Thanks for the comments - they are helpful. To be honest, I needed the roof done urgently as you know how windy it's been here the last couple of days - couldn't afford any more pieces falling onto cars below (not to mention people's heads !)
You're right - pricing structure would have been good to know. If these prices are high due to "danger money" ie. insurance and the rest, then that's one aspect. If you consider garage mechanics - there's certain danger involved in their work (handling carcinogenic materials, danger of fire, welding, vehicle lifts, heavy lifing etc etc) plus the huge cost of their equipment and other capital - yet they "only" charge €50 per hour.
You get a feeling deep down in the gut when you've been ripped off, even if you don't understand how or why, and that's what has me at the moment. Is there a building standards committee or something that roofers belong to ? Someone that could objectively say that such-and-such a job warrants such a cost ?