Are the joysticks potentiometer style or Hall Effect?
A brand new two axes Hall Effect joystick runs around $173 USD and a three axes Hall Effect joystick runs around $233 USD.
Additionally a good quality 12 bit joystick converter like the BU0836X is 49.99GBP plus FedEx shipping charges!
So how are you able to build your controller for between $200 - $250 USD?
You might want to check out these controller threads:
Regards,
TCIII AVD