There should be a step up program for runes
Say I have a tier 1 rune, I should be able to trade in that rune in an upgrade service for a tier 3 of the same quality. For example, I have the tier 1s of HP yellows. If I want to upgrade to tier 3, I dont spend 820. I only spend the difference. This will make tier 1 and 2 runes a legitimate buy short term and allow for a gradual full tier 3 build.