Charged different amount for in app purchase

I wanted to buy two items from a game: one cost 14.99 and the other 9.99, so a friend got me a $25 gift card which shouldve been enough to buy both

i bought the 14.99 one but when i went to buy the second one it said i didnt have enough funds remaining. i went to look at my purchase history and i saw the first item, but it said it cost 16.32 instead, leaving me with 8.68

on https://reportaproblem.apple.com/?s=13 my purchase shows up as costing 14.99

so which is it? how much was i charged? if it was 16.32 why was the price displayed 14.99? is there a way i can get the 1.31 dollars back so i can buy the second item?