。
The profiteering by farmers at the time was staggering.
Literal
That-time [possessive-の] farmers [possessive-の] profiteering [topic-は] was-tremendous.
すさまじい (tremendous/staggering) is a strong emotive adjective used for phenomena that exceed normal bounds — here describing the degree of 暴利 (profiteering/exorbitant profit). 当時の chains a temporal reference with の. The past form すさまじかった gives the sentence a historical narrative feel.