As a rule like most things, the more it costs to buy the better the quality the components are on the motherboard, and the better the motherboards chip set will be of the motherboard.
When you buy a motherboard that is cheap to buy Ambam the components and the chip set used on the motherboard will be of a lower quality and lack features that a more expensive board will cost to buy.
The capability of the chip set of the motherboard can have an impact on how well the cpu is used or utilised, and for example how much ram or memory you can fit to the motherboard in capacity or density.
And a more expensive motherboard will come with a lot more connectors or interfaces or expansion options.
Ranging from how many usb ports the board...