Mechanics and Fixing Any Questions Answered

Hello! I am wondering about v-brakes. I know very little about them and my mum has been complaining about the brakes on her hybrid. Basically the brake pivot is super stiff, so they don’t spring back away from the rim and rub on one side or the other. Upon inspection the pivot is a plastic thing (rather than the v-brake stud, which baffled me) and I can’t get it to not be stiff regardless of how I try. So I thought a change of brakes might be in order.

• are there sub standards in v-brakes that I need to be aware of?
  
• what’s a good, durable, not too expensive set of v-brakes?
  
  

Many thanks in advance