Well, the expensive parts are the electronics. Some of the servos cost around 40 Euros.
The PLA Filament used to print cost around 25-30 Euros per KG. If you print all successful its about 500 Euro for printing material and about 500-1000 Euro for the Servos and Electronics. Last but not least you need a 3d printer. If you don't have one you get nowadays good ones between 500-1000 Euro, the one I have costs 2000 Euro.