[KensRedZed]

That depends on what type of racing you do.

Having a race with a few friends or family members after dinner usually doesn't require a huge budge or special parts. Standard axles will usually work quite well.

Breaking the sound barrier or the speed of light requires a few upgrades like better axles, wheels, tires, motors, etc.

Racing in a competitive club requires even MORE upgrades. Especially when it's all about winning.