That sounds less coerced than bought. If so, the promised reward involved doesn't change what "consent" means, it only changes where breach of contract might occur.
A large economic or power disparity between the two may mean that there is not much difference between "coerced" and "bought".
It is just like someone running a sweatshop might be able to hire people for a couple dollars per day. The workers would be consenting to work at that price, but they are being coerced into it due to their own financial situation.
It is just like someone running a sweatshop might be able to hire people for a couple dollars per day. The workers would be consenting to work at that price, but they are being coerced into it due to their own financial situation.