It's typical in these situations that the price per stock is negotiated, with current SP as a starting point. It's fairly unusual, I think, for the company selling stock to get a price significantly higher than market price. It's more typical that there's a slight discount. At least that's been the case for every stock I owned where dilution has occured. We also don't know yet when exactly this deal was negotiated and approved, so it's hard to actually say. Considering where INTC has been very recently(below $20), $23.28 seems very reasonable to me.

The reason the stock surged up past $30 is the general market's reaction to the news, and subsequent buying pressure, not the stock transaction itself. It seems likely that once the exuberance cools down, the SP will pull back, where to I can't say. Somewhere between $25 and $30 would be my bet, but this is not financial advice, I'm just spitballing here.