You posit a geometric series an you expect it to not trend to infinity? Let's expand the series to 5 years, and we will use the constant of 3:2 that you provided as the index. Based on your series, the increase annually is x2, so we have:
3:2, 6:4, 12:8, 24:16, 48:32
$3, $6, $12, $24, $48
In five years a $3 candy bar will cost $48. While the purchasing power would theoretically remain the same, the government has no way to ensure that ratio remains constant. The result is that the denominator (cost) rises faster than the numerator (income) and the ratio becomes significantly skewed. This is the formula that required trillion dollar notes in one country.