Most silver speaker wire is actually just silver coated copper. There is a slight difference to my ears, but not one to write home about - in other words, I wouldn't pay a premium for it. The interconnects I use for SACD/DVD-A are silver and they do have a slighlty different sound (highs are a little more pronounced) than when using copper ones from the same company, but again, it is a very minor difference.
24AWG is probably going to be too thin for almost every application, so you are going to need triple or quadruple runs, thus eliminating the cost savings.