7. Amazon Basics Adjustable Dumbbells, $58
Weight range: 3 to 20 pounds per dumbbell
The Amazon Basics Adjustable dumbbells are a solid cost-effective option for adjustable dumbbells. The set includes two 3-pound bars, four 2.5-pound plates, and four 5-pound plates. Each collar, which screws onto the bars to secure the weight plates, weighs .5 pounds, so one bar could be loaded with more than 20 pounds. However, changing up weights mid-workout is difficult to do quickly thanks to the plate removal system.