I did many full installs with the 29$ dvd (ok, 25€ single license and 34€ family license).
the "problem" with the update dvd is simple - it's a retail dvd (thats whats printed on the box) - so what to do - retail is retail.
i installed the dvd's on different machines, some of them were actually mac's - the rest were hackintoshes (asus eee, sony vaio p, a digital engine and so on). i prefer the setup with an usb stick, faster and didn't get scratches.