It's just more professional and when I spend that kind of money somewhere I expect a certain level of communication.
When I order something from AP they:
1. send me a order confirmation
2. An email to make sure that I don't have any questions about my order and an estimated shipping date.
3. If I have any questions they are answered within 48 hours no mater how I contact them (email/phone)
sure none of that is necessary, but it did save me the first time I ordered something from them (I had accidentally forgot an add on that I wanted, and because of their email I caught it and they fixed it for me and sent me an updated order confirmation)