The sentence with a misplaced modifier is:
"I had only nine dollars, so I couldn’t get the necklace."
In this sentence, the placement of "only" creates ambiguity regarding what it modifies. It could imply that the speaker had only nine dollars (which is likely intended), but it could also incorrectly suggest a limitation on what they could buy, rather than how much money they have. To clarify, it could be revised to "I only had nine dollars, so I couldn’t get the necklace."