Navigating the labyrinthine world of media buying isn't a task for the faint-hearted. It requires a confluence of astute negotiation skills, acute understanding of market trends, and strategic deployment of advertisement budgets. As such, engaging a top-notch media buyer for your enterprise is akin to securing a valuable asset. Allow me to illuminate the process of hiring a media buyer par excellence who will optimize your advertising budget and amplify your brand’s market presence.

Media buyers, in essence, are the business counterparts of chess grandmasters. They strategically and judiciously allocate advertising budgets across various media platforms to ensure maximum brand exposure, all the while negotiating the best possible pricing. Their work is a delicate balance between economizing costs and maximizing reach.

To hire a media buyer of substance, you must first understand the core competencies required of them. These include market analysis capabilities, negotiation prowess, relationship building, creativity, and a keen eye for detail. The hiring process should be designed to accurately evaluate these competencies through a blend of strategic questioning and real-life scenarios.

The process can be divided into four steps: preliminary screening, behavioral assessment, task performance evaluation, and the final interview. The preliminary screening filters out candidates based on their qualifications and experience, using criteria defined by the specific needs of your business.

The second step involves a behavioral assessment, where you delve into the psychological aspect of the candidates, assessing their decision-making skills, conflict resolution abilities, and their propensity for creativity. This can be gauged through psychometric tests or situational judgement tests, both of which are grounded in the psychological theory of behaviorism.

The third step, task performance evaluation, involves setting up simulated tasks that mirror the responsibilities a media buyer would undertake. This could involve a mock negotiation, or a task where candidates are required to allocate a hypothetical budget based on provided market trends. This step not only assesses their job competency but also provides a preview of their modus operandi.

The final interview is a synthesis of all the previous steps and is essentially a value assessment. Here you assess the candidate's alignment with your company’s ethos, their passion for the industry, and their ability to be a team player.

There's no denying that hiring a media buyer is a serious investment. As such, it should be underscored by a meticulous and comprehensive process. Not every candidate will possess the required competencies in equal measure; the aim is to find the candidate who exhibits the perfect balance.

Technologies such as artificial intelligence (AI) and machine learning (ML) are playing an increasingly prominent role in the hiring process. These technologies offer the ability to streamline and automate certain aspects of the hiring process, such as preliminary screening or candidate profiling. However, despite their merits, they do present certain limitations. For instance, while AI can analyze data in ways humans cannot, it lacks the human touch required to assess behavioral competencies or cultural fit.

In conclusion, hiring a top-notch media buyer is an art and a science. It involves a thorough understanding of the competencies required, a well-defined hiring process, and where feasible, the strategic use of technology. The media buyer you choose to hire will be instrumental in shaping your company’s brand image and market presence. Therefore, this decision should be made underpinned by careful consideration and thorough assessment. The game of chess, after all, is won by the player who strategizes the best.