As per the statement made to Destructoid that I saw this morning, it looks like the price is lifting to 30 USD and sticking to its guns, with no planned sales.

Here is the quote from the article and the link below:

"The price of the game has been growing steadily together with the game becoming bigger, more stable and polished," said Wube Software. "After careful consideration, we have decided to set the new price of the game to 30 USD (or your regional equivalent). This change will become effective as of the 16th of April 2018. This is the final Factorio price update, unless something unforeseen happens, so it will also be the price for the game for 1.0 release."

Link: https://www.destructoid.com/factorio-is-wrapping-up-early-access-and-raising-its-price-496630.phtml

Thought it worth sharing here in case anyone hadn't seen the update.