Ha ha.  At least GOT my value with ZBrush, on the first release (4.0) I purchased.  If the last 2 rollouts of BS were not so disappointing I would consider taking the plunge.  BS3 to 4, then to V5 was so minor and some key features were actually removed... then the VirtualPaint debacle.  Now the main feature is a reversion to the old "working" interface but no real new block-buster features.  Have you seen the brush-set and vast capability of ZB?  It affords TONS of value, and the free upgrades were not just improvements to the product but substantial capability enhancements.  I think Blacksmith could learn alot from Pixeologic's approach.