I still buy Nicholson files from the local hardware store, because they are cheap and available and i don't have to worrying about ruining them on a piece of inbedded forge-scale or something like that. I've found the Mexican-made ones to be as good or better than the late American-made ones, which is not that high a bar I suspect. The Mexican-made ones are still in 1095, I believe, so the steel is useful as salvage.
A year or two ago I went on a file buying spree on ebay over several months and got a bunch of old new stock Grobet, Simmonds, and a Disston for reasonable prices. Haven't used any of them yet, as I am saving them for something worthwhile.