does it have to be a package deal? I can understand required components such as springs when you get the shocks. What about other things?
Do you offer the stiffening pieces separately? What about offering the K frame and rack together and allowing the user to source the related mass-produced items such as the GM suspension parts and more cost effective shocks and springs?
Break it into bite size pieces that are much easier to digest.

Many people on this board have over $20,000 in their cars but not very many of them dropped that cash all at once.