Hi,
Well cases are pretty cheap running between 80-150.us
You would have to also get a new modular power supply which again is fairly docile a good one for around 150.us

Your mother board in that case is actually upside down compared to a normal atx case would be = power supply on bottom left,

New wiring would come with the new power supply
A new case would have a false wall behind the mother board where wiring loops though and just the ends pop out holes where the connects are made,

cpu cooler in a new case with a new power supply minimum 750w
I would use a Corsair liquid cooler personally they range about 100-150.us depending on which one you get double length or single.

Then more case fans about 30.us a pair.

Plenty of examples here,
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