Which is it? Just the owners or both the owners and buyers?
Traditionally speaking just the butcher. Most would say there is no blame in buying meat since the intention is just to buy food. However this is a complex issue. It is true the buddha permitted the eating of meat. This should however not be taken as a rule to eat meat. Times were very different.
The product itself is unwholesome? In that case then how could any meat be deemed blameless by the Buddha?
Trade in meat as a profession is unwholesome. Meat itself is just meat, nothing more. Buying meat indeed is a way of urging a butcher to kill more animals so what is going on here? The buddha said not urge others to kill right.
Buying meat just to buy food cannot be the intention of a rational human being. You would have to be completely ignorant. The full intention must be this:
Buying meat just for food while not caring about beings being killed and not caring about urging the butcher to kill.
This cannot be a wholesome intention. What is true however is that it is still up to the butcher to kill or not. He doesn't have to kill, it is a choice he makes.
There is no simple answer to this. I would say this:
Do you care about the animals being killed: yes? then don't buy meat.
Do you care about the butcher accumulating bad kamma when killing: yes? then don't buy meat
Do you care about the worldhunger eating meat has a great part in: yes? then don't buy meat.
the buddha never bought meat!
Be aware that the buddha bhikkhus and bhikkhunis mostly ate scrap meat when they consumed meat. Meaning that it was forbidden if it was killed for them especially. And if they were prescribed meat as a medicine (wich happened) it was only to keep the body alive in order to eradicate suffering and teach the dhamma to humans and devas so they may be happy.
Also the most important thing to keep in mind that if all people in the world followed the 8thfold path, eating meat wouldn't even be possible! Who would be there to kill animals for meat? The buddha cared about human beings and other living beings. That means that global vegetarianism would have been one important results in teaching human beings if everybody in the world followed the dhamma. Not because eating meat as a substance is bad but because killing is bad and global vegetarianism would be a result of not killing. Unfortunately i don't see this happen any time soon
Make up your mind and be honest to yourself.