Mouser has the ATMEGA328-PU in stock. They are out of stock on the low power version ATMEGA328P-PU.
They claim to ship to Belgium for 30-40 US dollars and free for orders over $100.
1: $2.06
10: $1.99
25: $1.80
100: $1.70
250: $1.68
500: $1.63
So if you need 56 units (56 * $1.80 = $100.80). You can go into the Arduino Chip business in Belgium.