Simply put, ram prices are volatile, you never know what's going to cost what or why. About 3 years ago, after motherboards had all switched over to DDR3 ram, the price of DDR2 went through the roof. No reason I could figure, maybe it's the beginning of the same for DDR3 now that DDR4 is coming out. I found those modules in the US for ~$40 so I'd say the real question is "are they actually selling the stuff for 78€ or is that simply the asking price"