Positions corresponding to "Lecturer" do exist in the American university system. Tenure is more about job-security than about high pay, so actually "real" professors aren't that expensive[1]: $65k/year for a starting assistant professor, and $95k/year for a full professor (and most tenured professors only make Full Professor towards the end of their career, if at all).
[1] -- https://www.higheredjobs.com/salary/salaryDisplay.cfm?Survey...