I'm sorry, you're wrong about this. Although I will agree that this may be the case with some manufacturers - but definiatly not all.
The multiple more open PCI slots is also wrong cause motherboards with parts integrated come with less open slots (why should you need them is their idea). So most Mobo's without IGP, come with an AGP and 4, 5 or even 6 PCI slots and they still have USB, ATA, Sound, and probably also LAN integrated.
Your "integrated" mobo comes with the (cheap) video integrated no agp slot and 3 or 4 open PCI slots.
It's not necessarly the option with most expansion options, in contrary.