Hi Keith
I had the aerial mounted by a company called SkyTech who supplied the mast , brackets etc, and charged £59 for the whole job.
The aerial has a plastic coating, and it was mounted "out of the box" - I believe the fitter applied some silicone at the connector where the cable enters the aerial, but apart from that it's all as it came. It's been up for over 18 months now, and so far, no problems.
The aerial itself, along with the cable ready-fitted with connectors, including a patch lead for connecting to the RadarBox itself, cost £127 including postage, from Airband-Online of Macclesfield.
Hope that helps
Rod