So here a more detailed list of parts:

X525 frame 20€

Flysky FS-T6 Transmitter and receiver €40

FLOUREON 14.8V 5000mAh Lipo €40

Arduino Uno € 25

GY-87 IMU

ABS 10x4.5 "1045 1045R CW CCW € 3

rocket switch :D € 3

4x 2212 920KV Brushless Motor + 4x 30A SimonK ESC Quad Multirotor X525 F450