"Det" is used as a placeholder, because "verdiene våre" has yet to be mentioned in the conversation. Once "verdiene våre" is mentioned, "de" would be the correct pronoun to refer back to them. You could also use "de" if it was somehow apparent to the listener that we were talking about a plural something, even if that something was yet to be named.
It's similar to what happens here:
"Det (introducing a new noun) er en bil. Den (pointing back to said noun) er blå."