Runes Honestly Need to be a Little Cheaper
Let's face it Riot, we know you'd rather have us spend our IP on runes and buy RP for champs, but that just isn't a practical outlook on League for most (90%+) of players. (that's the REAL reason you can't buy runes with RP) If the price of T3 runes was reduced to be more in line with the stats they provide and their T1 and T2 counterparts (10x more for +2 armor) then people might even be willing to pay the unreasonable price you set for rune pages. Think of it like this, runes are the stats, pages let you diversify. Hindering someone because they don't the extra IP to buy the runes they want to play a champ is honestly a little bit mean. And having to decide no whether to buy and fill one more page or buying 2 or 3 6300 IP champions is outrageous.
TL;DR : Even like a 50% reduction in rune prices would put runes on an affordable scale, and more players would be on even ground because they can actually AFFORD to fill their rune pages.
EDIT: Someone mentioned what would probably be another alternative that might make Riot happier (aka we'd still spend a lot of IP on Runes instead of champs). Lazergamer suggested that runes be parts of the rewards system, where after X number of games you could unlock a free mark, then seal, than glyph, etc. I'm not asking for a shortcut to be a "good player". I just don't like the idea of paying 20K+ IP to fill a rune page that helps 2-3 of my champions.