Cheap parts are really not up to standard and you'll need to replace more often.
I've worked on too many cheap bikes customers bought from places like halfords or out argos and believe me its a nightmare.
They are cheap for a reason.
Higher end, well you should expect quality components. I mean you wouldnt buy a Ferrari and expect to find a ford escort engine under the bonnet.
Heres a more bike orientated example. Cheap bike - £99 suntour fork. Expensive bike Fox 36 or 38.
Which fork would you expect to survive prolonged use in rugged offroad conditions ?.
Hint: It's not the suntour
In fact in all honesty the suntour rarely survives light duty commuting for very long. Again, it's cheap for a reason.
Overall cheap bikes are a false economy.