In Resident Evil 4 Remake, the Merchant can be found in various locations. When you talk to him, you can buy and modify weapons. He's an iconic and essential character in Resident Evil 4.
Buy Weapons & Items
You can purchase Case upgrades and weapons, including handguns, shotguns from the Merchant. Case Upgrades can be used to increase the size of your Attache Case, allowing you to bring more items. It's recommended you buy these as soon as you can.
Limited Items Could Become Available
There are weapons that can be bought on sale for some chapter. Weapons on sale are cheaper than regular price and it comes with attachments for free. Buy the weapons of sale as soon as you see it so save up or farm money.
Some treasures can be sold at a high price by combining with another treasure & gemstones. Selling the items separately could only fetch for a low price so do not sell immediately. Instead, fill up the gemstone slots and find out the highest price you can get before selling.
Weapons that you no longer use can be sold at the Merchant for money. The price you can receive is almost the same as the cost of modifying. After selling the weapon, you can use the obtained money to modify another one to make another gun more powerful.
Expand Attache Case
When the Attache Case slots have been upgraded, the slots would increase which increases its capacity to carry items & weapons. Having a large space in the Attache Case is advantageous so it is highly recommended to upgrade it in the early game.
Upgrading weapon is also available from the merchant. Each upgrade costs specific amount of money but it improves the capabilities of the weapon such as power, ammo capacity, reload speed, & rate of fire. This is essential since the enemies are stronger in the latter part of the story.
Higher Upgrade Becomes Available Starting Chapter 9
Initially, weapons can be upgraded up to three stages only. Once you reach chapter 9, you can upgrade further up to five stages. Also, with Exclusive Upgrade, the special effect of the weapon can unlock which can significantly improve the weapon's performance.
Whenever the knife is used for offense & defense, the durability gets reduced and if the durability reaches 0, it can no longer be used until it is repaired. It is recommended to prioritize upgrading the knife to increase the durability for efficient combat and lesser visit to the Merchant for repair.
Armor is an item that can reduce the damage taken and it is available at chapter 8. With this, your survival rate is increased so buy it for longer combat & repair when needed.
There are items that can only be obtained with Spinels, a reward from Blue Request Notes. Some of it are weapons, attachments, & Exclusive Upgrade Ticket so make sure that you have enough Spinels on hand to get the item that you want.
In the original Resident Evil 4, if you shoot the Merchant, he will never appear in the same location again. However, in this version, attacking is disabled when you are near the merchant which makes attacking by accident no longer possible.