I looked on the Adidas website for the info, you're right, there is the Brazuca 2014 Glider Ball which is the regular hexagon panels, priced on their website at £16, and also a mini ball at £10.
There are 2 types of ball available, the £15 is authentic as in it's made by Adidas, but is not "match spec", the £87 one is the precise same type ball they use in the matches.
You have the "Brazuca Top Replique Ball" for the lower price and the "Brazuca Official Match Ball" for the higher...