£299 - no way.
It is very good stuff though if you like just washing your car and not polishing/waxing every month.
It beads for a a good year or so and looks pretty impressive. The pro detailers will never recommend it as it takes their work away.
The kits on ebay are normally leftovers. Try to get a deal on it if you can. (Free) 
lol they wont recommend it as its not very good. Will last around 3 months at the most. Its chemically impossible to have something which lasts a year on your paint, the bond just will not hold! Longest i have seen was about 12 layers of collonite applied once a week, it lasted 8 months and even then the beads were not very tight. Any more than 4 layers of wax is a waste though as it will no longer bond to the paint.
Autoglym products are ok, i dont like them very much as they are messy and you need lots to make any progress.
A few layers of wax or sealant (or both) will last 6 months tops. The amount of contaminates in the paint that will need clay barring by this point makes it non worth while to leave it on any longer. I would never want a product that lasted a year, even if it did last that long!
