Can I Use Two Colons in This Sentence?

Conversely, the substitution effect moves in the opposite direction: as the price of breakfast cereal rises, so does its opportunity cost: other goods become relatively cheaper and thus more attractive.

The practice of using two colons in a single sentence is often discouraged, but it seems to me to make sense in the sentence above.

So is this an acceptable use of colons, or should use an alternative form of punctuation. If so, what?