The carbon 13 breath test is more expensive than the carbon 14 breath test when comparing carbon 13 and carbon 14. Both the carbon 13 and carbon 14 tests are tests that check for the presence of Helicobacter pylori. In comparison, the carbon 13 breath test is slightly more expensive and the carbon 14 breath test is radioactive and is not recommended for pregnant women and children. Both tests are not very expensive, with the carbon 14 test costing about $50 to $100 and the carbon 13 test costing about $100 to $250. If you have a medical condition, you should go to the nearest regular hospital for examination and take appropriate treatment measures according to the examination results.