Can anyone comment on why at any particular time there appear to be quite a number of second hand Cirrus for sale.
IMHO, it is because they have sold so many, so fast, and to a pilot profile which highlights younger (but well funded) pilots, that relatively more are bound to appear on the used market.
I had some figures from European COPA but can't find them now, but I think Cirrus have sold far more new planes in Europe in the last few years than Cessna and (especially) Piper combined. That kind of feed rate is bound to eventually show up on the used market - this is why their used prices are a bit depressed also.
I don't think the operating cost of an SR22 is significantly more than that of say a TB20. But the operating cost of anything fully owned is going to be silly if one doesn't fly very much, and a plane like an SR22 really needs an IR, but the European IR population has been pretty static for many years, and most of them are owners even before they get their IR, so my guess is that more Cirruses than other IFR types are going into the hands of non-IR pilots. Who in turn will get fed up sooner because they aren't getting the utility.