The cost of shotguns can vary widely, and the most expensive ones are often custom-made or crafted by prestigious brands with a rich heritage. Some of the most expensive shotguns are known for their craftsmanship, materials used, and attention to detail. Here are a few examples:

1. Holland & Holland Royal Over-and-Under:
   • The British gunmaker Holland & Holland is renowned for producing some of the world’s finest shotguns. The Royal Over-and-Under model, known for its precision and craftsmanship, can be extremely expensive.
2. Purdey Side-by-Side Shotguns:
   • James Purdey & Sons, another prestigious British gunmaker, is famous for its high-quality firearms. Purdey side-by-side shotguns, often custom-made for clients, are among the most expensive shotguns available.
3. Fabbri Over-and-Under:
   • Fabbri, an Italian gunmaker, is known for its handcrafted shotguns. Their over-and-under models, particularly the Class SL, are highly regarded and come with a significant price tag.
4. Krieghoff K-80:
   • Krieghoff, a German firearms manufacturer, produces the K-80, a popular over-and-under shotgun in the competitive shooting world. Customizations and high-grade materials can make these shotguns quite expensive.
5. Perazzi High-Tech Sporting:
   • Perazzi, an Italian company, is known for its high-quality shotguns used in various shooting disciplines. The High-Tech Sporting model, with its advanced features and customization options, can be among the more expensive choices.
6. Boss & Co. Over-and-Under:
   • Boss & Co., a British gunmaker with a long history, is famous for its over-and-under shotguns. These firearms are often custom-made to the buyer’s specifications, contributing to their high cost.
7. William & Son Over-and-Under:
   • William & Son, a luxury goods retailer in London, also offers bespoke shotguns. Their over-and-under models, crafted with attention to detail, are known for their quality and exclusivity.

It’s important to note that the prices of these shotguns can vary based on factors such as customization, engraving, wood quality, and other features. Additionally, limited editions or historical significance can further increase the value of certain shotguns. As the market and offerings evolve, new models may emerge as contenders for the title of the most expensive shotguns.