So I just purchased my second monitor, it was the cheapest one in the store and does not attach to my gfx card so I was wondering what the losses would be for attaching it to my motherboard

you lose the second monitor

Depending on CPU, the motherboard output may not actually do anything.
If it does work, you could still run into issues with framerates and resolution.
Best option would be to buy an adapter and use with GFX card.

** If you bought a monitor that only has VGA, just return that shit.