The governor may be an explicit commercial scenario:

• I bought/sold the book for $10. 001

• I got a refund of $10. 002

• Cost↝Locus:

  • The book is priced/valued at $10. 003

  • I bought it at a great price/rate. 004

Or the Cost may be specified as an adjunct with a non-commerical governor:

• You can ride the bus for free/$1. 005

Cost is specifically about payment requested in exchange for goods or services (including income and revenue). If an amount of money is simply treated as property given, acquired, or possessed, then Possession is appropriate:

• I bestowed the winner with a bicycle/$100. (Possession) (Possession#007) 006

See discussion of transfer, goods, and services at Possession and Theme.