Based on our research, below are some good vacuum cleaners that are under $100, there are handheld vacuums and stick vacuum cleaners in this list; some are corded, and some are cordless; some are bagged, some are bagless; just choose the one that meet your needs.
Eureka 71B Hand-Held Vacuum
Rating: 4.5 stars out of 5
Price: about $40
Bissell Pet Hair Eraser Handheld Vacuum, Corded, 33A1
Rating: 4.4 stars out of 5
Price: about $28
Eureka 96 B Quick Up Upright Cordless Stick Vacuum
Rating: 4.3 stars out of 5
Price: about $36
Hoover S2220 Flair Bagless Upright Stick Vacuum with Power Nozzle
Rating: 4.1 stars out of 5
Price: about $48
The prices of these vacuums may differ when you read this post, however, chances are they will be under $100.