I'm at 61k training points and have dumped like 200 million in there easy, I've had about 3 or 4 Red Chakra Runes (I think it's 3) So the theory that it's generally 1 Red Rune for every 20k Training points holds up.

Golds are a little more varied but I'm sure there's an average there too, I've had around 15-18 Golds, maybe more, most of them were junk.