Originally Posted by Bonzo Banana

$100-200 would be pretty much entry level especially closer to the $100 level. Absolute entry level is often a heavy steel frame (strong), budget single wall rim wheels (serviceable), freewheel based drivetrain (weak and short life but ok for light riders and use), basic brakes, derailleur etc. Some entry level bikes are poorly assembled and will need a good service before use, correct safety checks etc.

Secondhand could be a better option as long as you have some understanding of bikes and can recognise a damaged frame, heavily worn components and other issues.