Izmir Stinger
Deity
If an AI has sold every copy of a luxury resource but one, they will charge triple for access to it.
This seems like a bad deal, but if you have severe happiness problems (say, an old trading partner backstabed you right after flipping a Mercantile CS ally off of you) it can seem worth it in the sort term, assuming you can afford it at all.
I suspect that, with careful scouting, this 3:1 deal only ever needs be sort term, if the AI handles it the way I think they do:
If the overcharging AI has at least 2 improved copies of the resource, that means they must be trading it to another AI. Once you take the deal at three to one, they have no copies. When their deal comes up for renewal with their other trading partner they won't renew with that AI for the same terms because now they don't have a copy of the resource themselves, and they should charge triple for it. Their other trading partner should refuse to trade on those terms (they AI doesn't pay triple, do they?) and the deal ends. Now when your deal comes up for renewal the AI should say "this deal has strengthened the bonds between our nations" and offer to renew it at 3:1. If you decline, the AI will now have a spare copy of the resource because 2 renewals have been declined, and since it is your turn, you can snatch it up at a fair price.
So if I am right about their behavior, the price for the "last" lux is triple for 30 turns, and then normal from there on out. This seems reasonably attractive, and potentially worth the cost if happiness problems are severe and there are no other trade opportunities, affordable city states, etc. The only thing that can screw this up is if the AI picks up an additional copy of the resource between failing to renew the deal with the third party, and renewing it with you. There is a good chance that other AI is still in the market for this particular lux and has something to trade that this AI wants, since they had just such a deal recently, and now that the AI that is overcharging you has a spare, she can trade it to the third party for a fair price. Then when your deal comes up for renewal it is still her last copy :/ Also, obviously, this won't work if the lux in question is their ONLY copy so you need to scout their lands thoroughly to make deals like this work.
This seems like a bad deal, but if you have severe happiness problems (say, an old trading partner backstabed you right after flipping a Mercantile CS ally off of you) it can seem worth it in the sort term, assuming you can afford it at all.
I suspect that, with careful scouting, this 3:1 deal only ever needs be sort term, if the AI handles it the way I think they do:
If the overcharging AI has at least 2 improved copies of the resource, that means they must be trading it to another AI. Once you take the deal at three to one, they have no copies. When their deal comes up for renewal with their other trading partner they won't renew with that AI for the same terms because now they don't have a copy of the resource themselves, and they should charge triple for it. Their other trading partner should refuse to trade on those terms (they AI doesn't pay triple, do they?) and the deal ends. Now when your deal comes up for renewal the AI should say "this deal has strengthened the bonds between our nations" and offer to renew it at 3:1. If you decline, the AI will now have a spare copy of the resource because 2 renewals have been declined, and since it is your turn, you can snatch it up at a fair price.
So if I am right about their behavior, the price for the "last" lux is triple for 30 turns, and then normal from there on out. This seems reasonably attractive, and potentially worth the cost if happiness problems are severe and there are no other trade opportunities, affordable city states, etc. The only thing that can screw this up is if the AI picks up an additional copy of the resource between failing to renew the deal with the third party, and renewing it with you. There is a good chance that other AI is still in the market for this particular lux and has something to trade that this AI wants, since they had just such a deal recently, and now that the AI that is overcharging you has a spare, she can trade it to the third party for a fair price. Then when your deal comes up for renewal it is still her last copy :/ Also, obviously, this won't work if the lux in question is their ONLY copy so you need to scout their lands thoroughly to make deals like this work.