The new agony infusions do a great job of showing the difference between cost and value. A one-unit increase in value doubles the cost.
They work like this: +1 agony (resistance) infusions drop. You can use one in an infusion slot to give an item +1 AR, or you can combine it with an identical infusion to increase its number. Two +1s get you a +2, two +2s get you a +3, and so on. It can be fun in guild chat to see someone who has never seen how quickly doubling numbers grow. You need 16 +1s to get a +5 and 512 to get a +10.
Assuming a trading post cost of 20s per infusion (the last time I looked), a +5 infusion costs about 3.5g, including the cost of combining them. A +10 infusion would cost 102.4g, which rounds off nicely to 110g when you add another 7.6 for all those combinations. A +20 infusion would cost nearly 8000 gold ($1,876 at the current gem exchange rate) just for the combination costs and would also need more than a half-million +1 infusions.
: Zubon
Not sure that infused armor would be my first thought in bringing over mechanisms from Guild Wars 1. Bring back heroes!
Actually, GW1 infusion was great. It was completely free, pretty easy to get, and didn’t take up a slot that could be used for something else.