Final answer:
The highly complex item in the Krajlic's Portfolio Matrix that has a high importance of purchasing is the Strategic item.
Step-by-step explanation:
The highly complex item in the Krajlic's Portfolio Matrix that has a high importance of purchasing is the Strategic item. This item represents products or services that are critical to the organization's operations and require a high level of expertise and attention. Examples of strategic items could be advanced technology components or unique raw materials that are difficult to source and have a significant impact on a company's performance.