Not possible... we know a 300x3.0 fox steel spring weighs ~520g, and a 300x3.0 ti spring definitely doesn't weigh 190g. I'd say it'd weigh in the region of 300g, making the weight saving more like 220g.
Hard to give exact figures especially with the variance in weights between different brand ti springs but I reckon that's pretty close.
Yeah you're right. I was using my calibrated Burgtec scale for the Ti spring. Using a correct earth gravity calibrated scale makes the weight difference less.