This guy is right. Tier 1 runes are virtually for free. If you buy 2 rune pages full of tier 1 runes, you wasted a 450ip champ, big deal. You'll get more ip simply by winning more games thanks to these runes.
Tier 2 runes are way more expensive for slightly better stats. They would be worth it if you used these runes for a long time, but you don't. You'll replace them with tier 3 which are again a lot more expensive for a bit more stats. These runes are very overpriced but since you use them for the rest of your time on this game, they're worth it. You can buy a few champions instead, but how often do you use those champs? You use your runepages EVERY game. So they're worth.
Buy tier 1 first, as they're basically free, then skip straight to tier 3 for your long-term optimal runes.