A Volca in Europe is $200 (150€) - the eur/usd thing affects the prices of new hardware but not so much the prices of second hand stuff, so a Poly-800 is roughly the same price as a Volca (125-200€ for sensibly priced ones) around here and even a bit cheaper if you look hard enough (
here's a search on ebay.de). The ones that sell for more than that are either heavily modded or include extras such as a flight case, etc. Non-working ones sell for around 50-75€ (I'm just going by the results of that ebay search).
Poly-61 is around 200-300€ (275-400$), but it isn't that big of a difference given the Volca isn't too expensive to begin with.
Oh well, that is Europe for you I guess - a Playstation 4 costs $400 in the US and 380€ around here, which is over $500. Sorry for the confusion.