In D&D you get a chance to craft your own items. When you kill creatures sometimes if you roll well you can get skin or poisons and other items that can be used for weapons and armor. the high a character get the more they want to go hunting for the unique or dangerous creatures for their items are worth more and make better stuff. a lot of players like going after dragons for the parts or a dragon are worth a lot especially if you can craft the items and sell them. I know when I was playing and not GM/DMing I wanted to have dragon armor for some dragon armor can protect you from the elements  plus its helps some casters to protect them with out taking a hit on casting. dragon armor is considered light armor like leather and cloth. if you ware plate and you are a caster you can take penalties for wearing plate. you will be protected but what about the party you are with are you going to be able to heal them or be able to cast that magic missal. so when you are looking at gear you need to be aware of what you can and can't wear. Sometimes you get your hands on an item that can send you to a house or a place you can place your extra stuff that you can not carry with you. or you stumble upon a wizards place that lets you come a go as you want. this is the place you do your crafting to make the armor or the weapons that let you hit harder or protect you better from magic and other abilities that creatures can have to control you or try and fear you from attacking them.

There are items that you can make your skills better like a rouge be invisible or he's slit of hand better to get items from people without them knowing. or a fight to hit harder or a sorcerer to cast stronger magic or allow a cleric to be able to cast healing spells that can not be interrupted or dispelled. there is a lot of things that can made that are better if you can craft them yourself then going out to buy them. sometimes you don't always come to a town that is selling the items you are looking for anyways so its a good idea to learn to craft them. there are times were you can go for days with out meeting a person or come to a town you are out there in the wilderness in the elements living on what you have or what is in your place that you have. so getting to know what you and your party needs makes the game a little more interesting and fun.