With which champions would you run those runes and expect to be able to win lane? Nobody that I have uses 3 AD quints with the possible exception of vi and riven. If you were to use that runepage as an AD carry you will lose every trade and lose every lane unless your jungler/support does something spectacular.
Yes, for those of you who like to be anal about every minor detail, dargon was exaggerating the actual gold value of having runes. However it's very difficult to accurately measure the benefits of the ideal runepage. I'm sure you all know that seemingly small early game advantages mean a LOT given what is likely to happen in mid-late game when this advantage has been abused.
I used to be bronze V. I had a lot of problems playing ranked because I didn't know what champion to use and didn't have my rune pages full.
I'm still bronze III right now, but I'm almost at II. Before they added the rank system, sham and I were both somewhere around silver, but dropped to bronze over time.