The Gym Leaders are using Hyper Potions and I wanted to get some since my HP is more than 50, but the PokeMart doesn't have them. How many Gym Badges do I need to buy Hyper Potions and Ultra Balls?
In emerald, items in shops are not dependent on badges. Its just depends on the city that you buy from.
The shops that sell hyper potions and ultra balls are Fortree, Lilycove, Mossdeep, Sootopolis, Ever Grande Poké Marts.