Seeing as how I'm waiting for the Caravan Arc above any of the other arcs, since I love trading so much, I've been thinking of ways of making trading better. So I've come here, since my cluttering up of the Future of the Fortress thread is getting bothersome to some people.
So I've thought of these three things:
Advanced Ordering: Alright, let's say for example you're really... REALLY hurting for some Masterwork Steel Platemail. With advanced ordering, when you talk to a diplomat, you could negotiate not only for them to bring certain items, but a certain number of certain items with specific quality the next time they arrive. Now, because this is such a large demand, it'd be very reasonable for them to increase the price a good deal to go along with it. Couple with off-season arrivals (detailed below) this might equal a VERY expensive set of platemail.
Large Commodity Trading: There are alot of items that don't have quality levels, so I think it'd be prudent to group these into a special category: "Commodities". When negotiating purchases, there'd be two different screens, one for 'individual' items, or those with quality levels, and another for 'commodities' or those without. Caravans would NEVER carry commodities, but you'd be able to order them. In commodity trading, the items would have a set price (though it may fluctuate depending on supply and demand) and you can order as many as you like. You have to pay the cost of everything you order upfront, and once the caravan leaves, there'd be a series of other caravans that'd arrive all throughout the year with your commodity purchases, where they'd go to your depot, drop everything you bought, then immediately leave. The opposite would also be possible, with the ability to sell your commodities at set prices. When you sell (say, your huge stone supply) a number of hauling jobs to your trade depot would be queued, and your dwarves would carry the stone to your trade depot, where the constantly visiting wagons would then carry it away.
Off-Season Arrivals: While it's normal for the caravan to only come during one season of the year, I think it'd be useful to be able to talk with the caravan's diplomat and negotiate out an agreement where the caravan comes at different points of the year. This could be balanced by having them demand a fee, or having all their goods be a certain percentage more expensive.
What do you guys think?