Welcome to the Apple Discussions!
Bear in mind, the Apple Discussions is specifically for people who are having problems. You're not going to see hardly anyone here posting that they don't have any problems. That's the point of the Discussions. There certainly have been thousands of folks already who are NOT having problems.
You're free to read Apple's Sales Policies here:
http://store.apple.com/Catalog/US/Images/salespolicies.html
Note, it says:
Please note that Apple does not permit the return of or offer refunds for the following products:
1. Product that is custom configured to your specifications...
So, you cannot return a custom built MacBook (or any Mac) for a full refund. However, if there is something wrong with your MacBook (or any Mac), Apple will fix it.
Custom configurations are made at the factory as your MacBook goes down the assembly line. It truly is configured just for you. These custom-configured models go through some extra testing on their way out of the factory, so it will add a slight delay to your order. Since we have absolutely no idea where on Earth you are, we can't shop the online Apple store of your country and see what the estimated ship date is for you. You can do that yourself pretty easily. If you shop the US store, it says a black MacBook with 2GB RAM and a 100GB drive will ship in 1-3 business days.
Because Apple considers the part user-installable, you can install RAM or a new hard drive in a MacBook yourself without voiding the warranty:
http://docs.info.apple.com/article.html?artnum=25097
However, if you do break or damage something while doing the installation, the repair will not be covered by the warranty.
-Doug