My kids love pin trading and collecting. We have hundreds and hundreds of pins in our house. The pins in the parks are expensive and generally when we buy pins in the parks, whether mystery or single pins, we keep them. We hardly ever trade those unless we have doubles. They have things called booster packs which will contain about 5 or 6 pins. In the park they will cost you about $30 per pack. So about 5-6 dollars per pin. Still on the expensive side when you want to just trade them away. If you are in orlando I would check out the character warehouse. They will generally have some discounted pin packs and such. Doesnt matter what they look like since you will trade them away anyway. Try not to buy pins that are 7-15 dollars a piece for trading…you will not get anything close to that when you trade. Look for starter packstoo. They have a lanyard and like 6 pins. Its a great way to get started.
My kids like to have lanyards for thier pins while they are in the park but the mickey head backs are not great so buy some locking pin backs from amazon/ebay so the pins dont fall off the kids lanyard and get lost.
Pin trading stations are harder to find now due to covid but hopefully back to normal in Jan! In normal times they are everywhere. Most CMs have pins on them to trade. Just ask if you can see their pins. CMs ask that you dont touch the pins but just let them know if you see one you would like to trade. You can trade 2xs per spot.
It is fun to see what pins catch their eye and see them get excited when they find a character they like or a pin that makes the smile.