When you run D&D-style or dungeon crawling fantasy, how much treasure do the PCs haul away?
I don't mean get, I mean take?
Do they pick through and take the choice bits, or do they haul away every possible scrap and then come back again for more if they can?
My GM Experience
In my experience players want to squeeze every coin of value out of an environment. They'll haul away captured weapons, bits of armor for scrap, every single piece of coin and piece of salable material they can get, and then sell a map to the deserted ruins as a treasure map.
Nevermind people with Portable Holes. They'd keep their life savings in that napkin and keep it folded close to their bodies wrapped in protective layers of material. And then they'd haul everything from furniture to whole dead monsters back to civilization.
In the past I had guys who would make a quick calculation - find 10,000 gp in the AD&D dragon's hoard? That's 1,000 pounds of gold! A few mules costs a fraction of that, so bring some mules or send someone to go get some. They might ignore the copper pieces at first, but come back for them later (especially if they'd cleared the dungeon entirely.) They might give them away, but only after getting the XP value out of them.
This was especially common before I changed to a smaller, lighter coinage system - in D&D clones you generally find more treasure in your first couple of adventures than you need for gear, so you have spare you can use as seed money for mules and laborers. If mules cost a handful of gold pieces but can haul hundreds, they make perfect financial sense. If gold weighs so little relative to its value that you can carry a fortune in a box, they're just an expense.
My current players have gone as far as carving the locks off of doors to sell as scrap metal. They've taken a broken dagger handle back to town as loot. Nevermind coinage - and since they only need a certain minimum of wealth to maximize their XP gain, they don't even need to do this. Buy every coin counts when you need to buy things later.
My Play Experience
As a computer RPG player, I take everything I can carry - then I come back for more. Every game starts with a real dearth of money, so I start scrounging for everything of even the smallest sale value to sell. It takes a long time to get over that once I've reached the point where I don't need the money anymore. That's true even when taking treasure has no impact on XP/leveling/etc., as is common in computer RPGs.
As a tabletop RPG gamer, it's pretty much the same. My goal is to maximize the value I get. Mirado takes everything that isn't nailed down, and invested in a crowbar in case things are nailed down. The fact that most of our XP comes from treasure only makes taking every damn coin more important to me. 20,000 cp? That's 100 XP! Carry it out. We've done what seems like SOP in my past games, too - haul treasure to a more convenient point (like, near the entrance) for a final magical examination and to ease shuttling it up to the surface.
I suspect if wandering monsters were more of an issue, we'd be a bit more cautious about it. But generally that's not the case, and if it was, I'd just consider hiring guards and more hirelings and laborers part of the cost of the treasure. Heck, give them a percentage and I'll bet they'll find a way to get even more out. Plus the wandering monsters might have some coins and salable weapons, too - unless wandering goblins and orcs oddly leave their purses at home.
So how is it with your players, or with you? Take everything they can sell? Pick and choose the choicest bits and leave the rest?
(And PS - for those of you who want to rob the adventurers on their way home . . . keep this advice in mind.)