Well, although 10$ seems very high for me I’m not sure about all places in the UK.
Anyway, taking into account current exchange rates, it comes close to that in some european countries, and there are huge differences between countries not far apart.
As a very rough guideline, you may expect:
Around 7$ per gallon in Germany,
around 8$ per gallon in Holland, Italy, Greece (if at all available in the latter two countries!)
around 6$ in Belgium, Austria, Spain and France.
The lowest in Europe are Sweden and Croatia at around 3$ per gallon. That’s why we love aircraft with huge tanks here in Europe (unfortunately not the case with the Cirrus), so whenever we come around we plan our stops strategically to “save” some money.
Anyway, things have gone so far with general aviation here in Europe that we aren’t actually concerned that much any more about fuel price. As indicated, it’s the sheer fuel availability that is our big problem. Last summer I made an (otherwise) fantastic trip all around Italy in my SR20, and even operating lean-of-peak most of the time, we sure had trouble to make it between fuel stops.
As an aside, for the operators, the huge taxation on AVGAS here in Europe comes on top of huge landing fees ranging from 10$ for a small airstrip to maybe 50$ for a regional airport up to 200$ for an international airport! But that’s a whole different story…
Believe it or not, we are still flying here in Europe but less and less people are able or willing to afford it!