User blog comment:Double Slap/Percentage Statistics- Addition for Statistical Efficiency/@comment-24366122-20140906034241/@comment-5502249-20140906184007

When you buy Giant's Belt, you've bought 1013g worth of health.

If you upgrade it to Randuin's Omen, you gain 320g worth of health. If you upgrade it to Sunfire Cape, you gain 187g worth of health. In both cases, you aren't putting much money into health. If you were playing Rammus and were worried about Olaf, you'd buy another Giant's Belt and upgrade to both Randuin's Omen and Sunfire Cape later (or Warmog's Armor since it gives 1654g additional value to health if you needed it).