I have some concerns brought to me by a player and they are pretty valid. With the catch of cold iron covering all iron and steel weapons almost every Tom, Dick and Harry will have access to cold iron or steel.
I agree with chadu and Taskill on the 'definition of cold iron' front. On the game mechanics/balance front:
Consider that The Catch pricing says that the +2 level for accessibility covers stuff that "anyone could reasonably get access to, but usually doesn’t carry on them (like cold iron)". I think this description fits exactly with the interpretation that 'cold iron' includes anything that is an alloy of iron. If it meant some specialty forging technique or special mystical version of iron (like in D&D), then it would be worth less of a bonus.
Consider also that Fae are getting (up to) -4 refresh worth of powers for only -1 refresh due to The Catch. Even if the power only works on everything but iron/steel/alloys/etc, that's a LOT of benefit for only one refresh. It covers: fists, guns (except those using steel-jacketed rounds), most clubs, fire (and most other magical attacks), acid, sharpened stakes, claws, teeth, and a great many other things. It doesn't cover most blades, some bullets, and things like steel (but not lead or copper) pipes.
Yes, someone who knows they are hunting Fae and who does a bit of homework can make sure that they bring steel-jacketed rounds. But at the price, it's a
steal! And at the very least, it means that you have 2 armor and 4 extra physical stress to use when the wizard starts lobbing fireballs (which can't be steel-jacketed) at you, and that alone is worth at least one refresh, isn't it?