I don't know exactly what's possible.
But whenever you find a game gives sync errors, trial and error to see how exact the server is checking.
Change price from 500 to 499 or 501... If neither work, then might be something little more complicated and can't just make it 0.
Basically, just make very subtle changes and see what gets accepted. Then keep increasing until you find the threshold of what the server will give error.
Like with coins earned in level. Level 1, server might know, can't exceed 250 or something. Maybe at level 50, 1000 becomes the new threshold.