Well, it's a bit of a chicken and the egg, no? Microcontroller won't work without a (most likely) crystal oscillator or something to act as a clock signal.
Now that I think about it, no, it's not even cheaper as XTALs are quite pricy compared to other discrete components.
I didn't mean to be rude - I interpreted the comment as "Would you like to build an (insert random object here)? Well, you can just BUY it and be done with it" - may not be as I put it (dumb) but certainly... simplistic and purpose-defeating
Now that I think about it, no, it's not even cheaper as XTALs are quite pricy compared to other discrete components.
I didn't mean to be rude - I interpreted the comment as "Would you like to build an (insert random object here)? Well, you can just BUY it and be done with it" - may not be as I put it (dumb) but certainly... simplistic and purpose-defeating