Answer:
Around $60 or less.
Step-by-step explanation:
The first series in a set is about $30 - $25 and the entire second series is around the same price because they both include six books. It's a great series I know this question is older so you may have the answer already. The books individually are about $9 each though so it depends then it would be 9 x 12 = 108 and also you could get them used for cheaper.