Technically, you can save money since system builders do charge extra money beyond the cost of the components so that they have money to pay for normal business expenses (re-instating slave labor can help lower cost though) and also to re-invest in the company.
MSI does sell "whitebooks" which are stripped down laptops which generally does not have a CPU, RAM and hard drive. In some laptops (generally speaking) the CPU and RAM is already embedded on the motherboard (like some ultrabook / sleekbooks [AMD]). The graphics chip (if there is one) is also typically embedded on the motherboard.
In higher end gaming whitebooks, there is no embedded graphics chip. Instead there is an available MXM slot that is used to install an actual MXM form factor laptop graphics card. These MXM cards are difficult to find since they are generally not sold directly to consumers, and they are also expensive.
Below is a link to MSI's whitebooks, however, you need to find a place that will sell one to you. I don't think you will be able to buy directly from MSI unless you do a mass order.
http
/www.msiwhitebook.com/
Here is an example of a MSI whitebook that allows you to install your own CPU, RAM, HDD or SSD, and graphics card (GTX 770m or 780m).
http/www.msiwhitebook.com/product_spec.asp?model=MS-1763