Milton Keynes mate.
The question is, can you afford NOT to afford it?
If it gains me a few days work to keep me on schedule through any deep freezes, paid for. If it speeds me up on 1st cleans, connys, and fascias, then, paid for.
I have no issues at all with the cost and the justification of it, as long as it does the job of course, which it sounds like it will, and has been tested enough, so, I am happy.