I searched arouond and everywhere seems to be £15.99 a can.
I did my wing mirrors in black at the weekend and it came out great. Its a shame it spat with rain slightly so there are some minor bobbles in it, but other than that its perfect. The Plastidip sort of 'self smoothes' so its really easy to get a smooth matt finish.
Really impressed with it.
Its also worth noting that while it may look expensive at £16 a can, in the bigger picture it can be cheaper than paint. I did another set of wing mirrors and that required a can of primer, the paint itself, and then a clear lacquer, which together came to over £20 for the same job. The Plastidip needs nothing more than itself.