I can only speak for myself, but I can honestly say that I spend about 50,000 dwarfbucks a year on gems. I'd gladly spend more, but there's no
Buy All option, and my patience is limited. Also, my workers are lazy and indolent.
I'd hate to start rambling off in the wrong direction, so forgive me if I'm missing something, but transporting goods by land tended to be exorbitantly expensive for most of history (at least as far as my understanding goes). I can understand that applying this to Dwarf Fortress as it currently stands would be a bit odd. Merchants just show up on the edge of the map, after all, and there are no real transportation costs to speak of.
If there were transportation costs, however, I'm having trouble seeing why bulk wouldn't be a factor.
Daily life in the Roman city: Rome, Pompeii and Ostia certainly seems to suggest that, with "Transportation of bulk goods by land was prohibitively expensive and slow." (p.198) ...After previewing my post, I'm not entirely sure that the link works... It goes on to say, though, that hauling a wagon-load of wheat was something of an exercise in futility, as the animals required to haul it would rapidly eat a wagon-load of food themselves. I realize bulk cargo isn't quite the same as bulky cargo, but I think the point remains, especially for something so cheap as to be effectively free, like logs in DF.
Trade, transport, and society in the ancient world: a sourcebok [
sic], meanwhile, discusses the increase in price as a function of distance. Page 134 includes a convenient excerpt from the Edict on Maximum Prices, allowing you to calculate your shipping costs in wagon-, camel-, and ass-loads per mile.
If I've missed the point completely, or if this has already been covered, feel free to disregard all this, of course. In summary (bulleted for your convenience):
- I buy too many gems.
- In the 4th century Roman empire, it apparently cost 4 denarii to transport an ass-load of freight 1 mile.
- Either my linking abilities suck, or I fail at Google Books.
Edit: Having read ManaUser's post, I can only speak for myself, but I can honestly say that I would gladly spend about 50,000 dwarfbucks a year on lumber. But patience is limited, workers are indolent, etc...