The only negative point is that the prices are outrageous, but it's worth every penny.

outrageous 是由名词 outrage（暴行、愤怒）加上形容词后缀 -ous 构成的形容词，意思是"极其过分的""令人震惊的"，在这里形容价格高到令人难以接受的程度。