These PowerBlock Sport Adjustable Dumbells are currently marked down to $100 (reg. $159.99). While this does seem pricey, they take up way less room than having many sets of dumbells and you can adjust the weight size from 3-24 pounds in three pound increments. They also travel well.

• Item may ship in more than one box and may arrive separately
• Pair of adjustable dumbbell weights for efficient, cost-effective strength training
• Adjusts from 3 to 24 pounds in 3-pound increments (3, 6, 9, 12, 15, 18, 21, and 24 pounds)
• Selector pin lets you change weights easily, just like with weight stack at the gym
• More compact and balanced than traditional dumbbells; padded handle for wrist protection
• Offers maximum weight of 24 pounds per hand; limited 10-year warranty