@Hammer
THat MSI board is also almost 2 years old, so it's EOL. Right now, nobody has PPC clone boards that are that old.
So let's deal with boards that are currently being produced. The cheapest I've found in an EPoX board, the EP-8KHAL, which is an old design they've kept in production. That costs $79 on pricewatch.
Just the motherboard.
It is more than possible to get PPC down to that scale.