That is really hard to predict in my opinion. I think though that we have seen the first impact of this news already. That was when the price of Ethereum went up pretty quickly to almost 2000$ like two weeks ago or so when the news become public that the merge was successful on the testnet and that it will go live earlier than expected. Since then the prices keep on dropping tough and ETH was below 1500$ a few minutes ago. So i would say the first big effect of this news is already gone again. I think that if the merge is successful the price will go up a bit but not that much. If it fails though then i think the prices will drop significantly.