Both W3 and S-Builder Co-op are very important tool in growing your business at SFI.
If you are taking about Building a team at SFI, no doubt that S-Builder is the better option.
But of course, when it comes to cost, S-Builder is much higher.
But if you are talking about added quick VPs and MRPs, Wave3 is cheaper (or almost no cost at all). This is also a good window for promoting and advertising your business at SFI.