I mean at what cost or quality level does a bicycle go from being a BSO to a "real" bicycle?
Looking at Shimano (for mountain bike or hybrid), you have these quality levels:
Deore SLX or LX
I did read messages claiming Acera and 2300 shifted well enough and other messages stating the jump from Alivio to Deore or Sora to Tiagra is a significant one. But, do you need to buy Deore/Tiagra to have a real bike?
Or is it a certain cost? Some bicycles have Acera front and rear derailleurs for $400 with V-brakes and rigid forks. But, other bicycles with Acera with disc brakes and suspension forks can sell for $600. So, where do you draw the line?
Or, is it more specific things like whether a bike has a threadless headset and cassette instead of a threaded headset and freewheel?