Vista Upgrade Key with OEM Install

[allenpg]

I've got the Vista OEM Installation DVD for clean installs and was wondering if I could get away with using an Vista Upgrade key on a new OEM install (after it was installed). The reason I ask is that it's a lot cheaper getting a Home Premium Upgrade key through an education discount than getting another OEM license.

I would rather not have to install Vista (again) with the Upgrade DVD and just use the key.

Thanks for the help!
-Pete