How much is from closed source drivers?

I wonder how much of the return rate is because of cheap hardware that does not have opensource drivers. I just purchased a Dell netbook for my son (still waiting on it actually) but did not purchase the Acer or earlier models because they came with odd versions of Linux (the Aspire One comes with Linpus Lite?!?) and from my research it was a days work to try to get the mic and WiFi working if you installed Ubuntu, and then I read conflicting reports about how well the mic worked. My son records simple things for band projects with Audacity, so a non working mic would have resulted in a return. So how much money did they save by going with hardware that only has closed source drivers?