How to Use the iTunes 4.0 Music Store Shopping Cart
To buy music using the shopping cart:
1. Open iTunes.
2. From the Preferences menu, choose iTunes.
3. Click the Store button at the top of the window
4. Click the checkbox labeled "Buy using a Shopping Cart."
5. Click Music Store in the Source list, then find the song or album you want to add to your shopping cart.
6. To add an item to your shopping cart, click Add Song or Add Album. Items remain in your cart until you're ready to purchase and download them. To remove an item, click Shopping Cart in the Source list, then click Remove next to the item you no longer wish to purchase.
7. When you're ready to buy the items in your cart, click Shopping Cart in the Source list, then click the Buy Now button in the bottom-right corner of the cart.
Important: Once you click to buy the items in your shopping cart, you cannot cancel your purchase.