The pack costs the same, there's just less inside.
Shrinkflation is a hidden price increase: instead of raising the price, the maker reduces the contents. 200 g becomes 175 g, 1 litre becomes 900 ml, and the pack looks identical. At the same price that's a 14% and 11% increase respectively. Consumer groups document such cases regularly because hardly anyone compares the grams.
Useful: Never compare pack prices; always compare the price per kilo or litre on the shelf label.
Source: en.wikipedia.org