I agree with Robert. You will probably end up paying about the same for a throwing knife as you would for a high quality cutting tool. You might save some cash on a thrower because they typically don't have handles(although a think Jerry Busse has made some custom throwing blades for guys that hunt hogs, and I believe that they had handle scales). You may also save because a maker might prefer using s30v, ats34, 3V, d2 etc. for a cutting/chopping knife to have really exceptional performance. But since we are talking about a throwing knife here, I would lean toward using a tough spring steel like 5160. The knife is probably going to be hardened to 48-50Rc(or to a spring blue color) 5160 is a lot easier to forge(I wouldn't attempt forging of the steels I mentioned except for 5160, the others are air hardening steels and take very controlled temps to optimize performance) and grind than the other steels I mentioned. This means the 5160(or similar steel knife) will cost less because it will take fewer belts. Also 5160 can be heat treated by the maker in house with a coal forge, torch, gas forge, salt pot,etc and save time and money shipping to the heat treater. Hope this helps...
Ss