Ample quantities of stock have been available between 27 and 28...

Ample quantities of stock have been available between 27 and 28 cents both yesterday and today (esp if you include options being available in that price range). That is only 8% to 12% more than the placement price.

Given that the price being down at these levels is likely a direct result of the placement announcement, in a way it could be said that there has already been an opportunity to get stock pretty close to the placement price that would not have presented itself without the announcement.

Anyone that can't be bothered picking up stock at 27c on-market is highly unlikely to go to the trouble of subscribing for stock at 25c via an SPP.