Buy an old one. I buy most of mine off of ebay, a jennings brand is always a good knife. I have them with fixed and with folding handles. Great tool. Don't be afraid to buy one with the folding handles either. Buy one with a slight curvature to the blade, not straight. The ones with more of a teardrop shape handle have always afforded me more control and are just more comfortable. These are just my opinions and preferences, except for the part about buying an old one, this is just the best way to go unless you have the $ to buy a new one with the quality of the old ones , and I mean $$$.$$
No matter how cheap they are do not spend any money on one of the those push knives either, they are beveled on both sides, I hates em. A draeknife with a single bevel is by far the better choice.
