I don't know exactly how much you're willing to spend, but a Craftsman 2x42 is ~$160 new, and you can get great deals on Craigslist etc. There's certainly nothing wrong with filing, in fact I would say that's the best place to begin, but you're better off not concerning yourself with time if you pursue that route. Your only worry should be perfection, not speed. You should check out the stickies.