Back in the day I dealt with ‘unimportant’ shopping with a tome which we referred to as the GURPS Argos Catalogue. The house rule was, that anything the characters wanted (and could afford) which was in the Argos catalogue, they could just have, without bothering me with a shopping expedition or queries as to price. If they wanted to buy stuff not in the catalogue (like firearms, illegal drugs or pet leopards) then we’d roleplay it. These days I guess it would be the GURPS Amazon Website.
The downside was that their spaceship and the filled up with plastic lawn chairs, clocks which tweeted realistic bird song on the hour, sets of golf clubs and other tat which they’d found when browsing the catalogue!
On Roger’s WWII campaign, and why the characters don’t exploit their position more, my view on it that we are playing soldiers, not adventurers. Subordination is part of the mindset of a soldier, and not meddling with politics is a specific part of the British Army worldview. We also lack the background and skills to do it well, and the people in charge seem to be doing a pretty good job.
When we meddle with history, we do it very carefully, and in accordance with the policy our commander made a while ago: try to shorten the war and save lives, but don’t take risks with the outcome.
Mike might like to note that GURPS Dungeon Fantasy 8 - Treasure Tables includes a set of random magic item generation rules, mostly but not entirely based off the GURPS spell-magic system. I doubt that it’s unique in this; dungeon-bashing sorts of games like their (a) magic items and (b) random generation tables. Of course, such rules will tend to the rather prosaic dungeon-bashing-game view of magic.
(I’m still proud of the Random Vancean Costume Generation Rules that I did for the Dying Earth RPG…)