Spring stock, 1075, 1075, 1095, is not overly expensive. It never makes sense to me that people will risk sometimes large amounts of effort failing, so that they can use scrap of unknown properties. Having some tool steel and some spring stock in the shop is just like investing in good chisels and rasps. MSC and McMaster Carr can supply a variety of configurations of steels; buy only what you need for a current project and mark the unused portion with a paint or magic marker for future use. Home spring making is a skill, but your hardening and tempering to make springs will be more successful when you know what material you are working with.