Seems busted to me, the condition feels quite easy to fulfill even with little build-around and its effect synergizes with itself so you can chain these together and they even dig out copies of themselves. Considering the card is a common, that's a huge issue since it means you could relatively easily end up with some 4+ copies of it.

­ instant to draw three is getting close the Ancestral Recall levels of busted.

Getting some Library of Alexandria vibes design wise except you can throw this optimized out with and even then end up with just six-seven cards. It would be good to clarify btw that the card doesn't count itself while being cast (whether it actually does or not). I would adjust the numbers around a lot here. Maybe and sorcery? So there's some awkwardness at least when thrown out at optimal mana cost.

Also probably not the healthiest card to have common so I would consider upshifting it to uncommon.