The more you buy, the less you pay. Always ask for their pricing brackets to see if a slightly larger investment could significantly boost your margins.
Depending on your jurisdiction, you will need a general business operating permit. how to buy wholesale products
Most wholesalers require you to buy a minimum amount (e.g., 500 units). If you are a new business, you can often negotiate a lower "test" MOQ for your first order. The more you buy, the less you pay