Recently acquired a refurbished M52 for parental unit use as e-mail/word processing machine, and ran into a problem.

The machine it's replacing was a tower design in a cabinet under the desk, but the M52 is in the desktop format. Looking around for the official stand (part # 39M0589) on Google, almost nowhere is listing an actual price, insisting that potential buyers send a query, and the one actual solid price I saw was $140 (more than I paid for the system, shipping included!).

For a casual home environment, is the stand absolutely necessary, or can the case stand on its end without problems?

I don't think it is an issue, just make sure that if there are vents on what will be the bottom, put some sort of "feet" so there is airflow - other than that I don't think there will be an issue, especially if there is a cabinet to protect it.

One of the two sides doesn't have a vent on it, opposite from the end of the case with the PSU exhaust fan, so I'm guessing the no-vent side is supposed to be the "down" side in a vertical configuration, making ventilation a non-issue as far as that goes. Might try to rig up spacers anyway, as the case itself can also radiate heat a bit (being metal and all).