Skilled negotiators seek to understand the needs of the other parties, as well as their own. In doing so, it allows them to determine a strategy that their own needs are met. Failing to understand the other party's needs is one of the most common reason for an unsuccessful negotiation. In the commercial negotiation, procurement team does not negotiate with organisation, they negotiate with individuals. It is therefore important to recognise that there are two levels of needs:
The organisation - What the organisation wants to achieve. This is generally well stated and understood The individual - what is in it for the individual? This is generally not stated, rarely discussed, but very motivational. It is vitally important therefore that time is invested in understanding the needs of the individual Skilled negotiators are aware of the needs that occur at both levels, and develop creative options and strategies that attempt to satisfy these needs.

MIL criteria indicate 3 limits that negotiator should establish:
M - Must achieve: minimum target/maximum you can concede on this point; the mandatory requirement or fall back position I - Intend to achieve: realistic target you are aiming for on this point L - Like to achieve: stretch target to achieve on this point.
PPCA is purchase cost analysis
TIMWOOD indicates 7 types of waste in Lean principles
The RAQSCI model is a mnemonic summary of a business model used to define and structure business requirements

Whenmany supplierscompete forfew buyers, buyers gain leverage. This competition can drive prices down and increase the buyer's ability to negotiate favorable terms. Conversely, if the buyer is dependent on a supplier (as in A), the buyer's power diminishes.
"Buyer power increases when there are many suppliers and few buyers. The buyer has multiple options and can negotiate from a position of strength." (L4M5 Commercial Negotiation, 2nd edition, Section 2.3 - Relative Bargaining Power and Market Dynamics)

Monopolies exist in many markets in real life for very different reasons:
Ownership of a Key Resource: When one company exerts sole control over a resource that is necessary for the production of a specific product, the market may become a monopoly. For example, the only medication deemed acceptable to treat a disease comes from a particular ingredient X, and knowledge of this ingredient X is owned by a single family owned company. The company can, therefore, be said to have a monopoly over ingredient X that is needed to cure the disease because it is the only company that can produce a product deemed acceptable.
Government Franchise: In certain instances, a monopoly may be explicitly created by the government if it grants a single company, whether private or government-owned, the right to conduct business in a particular market. For example, when a national railways transportation service is created by the government, in most cases they are granted a monopoly on the operation of passenger trains in the country. As a result, other firms are only able to offer passenger train services with the cooperation and/or permission of the government- owned provider.
Intellectual Property Protection: Extending intellectual property protection to a company in the form of patents and copyrights is yet another way in which monopolies are created. When a government does this, it is in fact giving a single company an exclusive right to provide a particular product / service to the market.
Patents and copyrights work in providing owners of intellectual property with the right to act as an exclusive provider of a new product for a specific length of time. This creates a temporary monopoly in the market with regards to new products and services.
Natural Monopoly: A market may also become a monopoly simply because it may be more cost-effective for one company to serve the whole market than to have several smaller firms in competition with one another. A company with virtually unlimited economies of scale is referred to as a natural monopoly. Such firms become monopolies due to their position and size, which makes it impossible for new entrants in the market to compete price-wise. Natural monopolies are common in industries with high fixed costs and low marginal costs of operation such as providers of television, telephone, and internet services.
In this question, 'A single firm is very large' is not enough to tell whether this market is monopolistic.

Direct costs are those costs of a product/service directly attributable/traceable to its production. Examples of direct costsincluding the following:
Materials and services bought-in: In steel manufacturer, raw materials are iron ores, scrap metal, coals, etc Labour or wages: money paid to staff for the work involved in producing the product.
Other expenses: other charges incurred that can be specifically attributed to a particular product, batch or service