A long time ago, it seems now to me, I thought it a good idea to refurbish a rifle and was too poor and ignorant of what I should properly do to do it correctly. So much work and long hours that extended well beyond the low cost of rifle and parts proved that I ended up with a well made piece of junk.
Go for broke. If you have confidence, and you will, you will better and sooner learn.
Listen to these guys here, as I have about the questions you ask concerning knife making and steels. My advise is to purchase knife steel made for knives or tool steel that is suitable because you will be working very hard to finish something you will not know any definative thing about until it is finished and finally put to the test.
Your question has probably been answered in the previous posts above but my point is: spend as much as it takes to parallel the efforts you put into the product you wish to make.
Roger