Government contractor did not waive statutorily mandated offsetting payments in contract terms that elected the governing administrative regulation that prohibited such offsets, since the government counterparty to the contract was required to follow the regulation that was contrary to law.
Government would have to at minimum identify a viable avenue of judicial redress available to contractor at formation.
Tucker Act jurisdiction for an illegal exaction claim requires nonfrivolous claim that the government, in obtaining the money, has violated federal constitution, statute, or regulation -- establishing that the claim is "money mandating" is not a jurisdictional threshhold.