The law says that your ability to buy and sell things is based on the general rules about making contracts and owning property. This means that if you're allowed to make contracts and own things, you can buy and sell goods.

There's a special rule for people who can't make contracts because they have mental problems or are drunk. If someone sells and gives them things they really need, they still have to pay a fair price for those things.

The law explains that "things they really need" means items that fit with how that person usually lives and what they actually need at the time they get the items.