Scaling price dependent on what you need to complete the set.
For example, I have W1 and W2 on GOG so can purchase Witcher 3 GOTY, Thronebreaker and The Witcher Adventure Game for A$23.87.
This is a fantastic deal as the current lowest price for Witcher 3 GOTY is $23.17 and the lowest for Thronebreaker is $19.74 (also at GOG).
Toss a coin to your witcher~