;; string->float inputs from pc-settings.gc
(defun sf-scaled ((s string) (scale float))
  (the int (* scale (string->float s))))

(+ (sf-scaled "0.3" 1000.0)      ;; 300
   (* 10 (sf-scaled "50.0" 1.0)) ;; 500
   (* 10000 (sf-scaled "0.25" 100.0)))  ;; 250000