Here all prizes are presented as the amount you receive on your bank. Taxes are 25% on lotteries for prizes above 450€, so a 30.000.000€ grand prize is actually 40.000.000€.
But there is another problem: the old-years-eve lottery, happens at 31st of december, so if you win 30mil, your average bank balance for 2011 is 15mil (even though it will be transfered not earlier than february/march!). You pay wealth-tax over that: 1.2%, which is 180000€. You have to pay it on the 2011 tax period, and it might be claimed from you before you actually have the prize!
Most winners don't have 180.000 at hand
.