Flight Kunming to Datong October 3rd

Hey there,
I would like you to give me some advice - since I know there are a lot of experts here :-)

I need the Lucky-Air Flight to Datong on October 3rd, the Saturday during Golden Week and like I was told the busiest day of the year. Well, I could book the flight right know, but it is nearly 350 € .
You think the flight will get cheaper? Or is it posible that it will be booked out when I wait for some time more?

Thanks for your opinion!