Woot! has select PowerBlock Dumbbell Sets on sale listed below. Shipping is free for Amazon Prime Members (must login with your Amazon account and select a shipping address in order for Woot to apply free shipping) or is otherwise $6 per order.

Thanks to community member HomerJay for finding this deal.

Available:
PowerBlock EXP Adjustable Dumbbell Set (Select from drop-down menu):
Stage 1 Dumbbell Set (5-50-lbs, pair) $199.99
Stage 2 Expansion Kit (50-70-lbs, pair) $89.99
Stage 3 Expansion Kit (70-90-lbs, pair) $89.99