if you can, become an auction-hound.
Almost every file I use, I got at auctions.
I picked up a nice lot this past Friday, all Nicholsons: 2 mills, 3 pillars, 2 xtra fine barrettes (I think they're called), and two 3-cornered.
All in great shape.
Price: $4.00
yeah, you'll hit 3 bum auctions for every good one, but that's half the fun !
/mike