Time is rather tight, you'd better leave more time for this trip.
I googled and found the flight ticket with lowest price is about rmb600, then cover the entrance ticket,the taxi (to save time)fee from the airport to the scenic area ( about rmb150) and the accommodation fee if you arrive at night. You can work out the cost based on your request. BTW, there will be more visitors on the days,for it's the mid-autumn holiday.