If the prices are the same or similar to Disney World, they start around $14.95 and go up based on how elaborate they are (sequins, added decorations/flair, etc...)
The pair I bought in the parks was $24.95, I believe, they're gold sequins with an applique and feather.
Most of my ears are customs from etsy, but I'm 98% confident that I've given you accurate info
I have these and I recall the prices being the same in the parks as shown here. The online store has very little in the way of selection, but you should expect $20-$25 each, depending on the headband.