sentence construction - "as much as me" & "as much as I"

Sentence 1: He doesn't earn as much as me.

Sentence 2: He doesn't earn as much as I.

In sentence 1, the second "as" is a preposition so it is followed by an object pronoun. In sentence 2, the second "as" is a conjunction, and the complete sentence should be "He doesn't earn as much as I earn". Am I right?