OUAC Fees for students in an American Highschool

Can someone help me understand the fees. It seems that you have to pay $156 for 3 universities, but whats the “Supplemental/Document Evaluation Fee” and why is it so expensive.

The supplemental/Document evaluation fee is the fee paid to each university you apply to, similar to application fees for US universities. The $156 is for OUAC to send your documents to the university (similar to the Common App). The OUAC fee is paid by Canadian students too.

US universities charge much higher application fees for students who don’t attend US high schools and Canadian universities do the same. I had to pay about double the regular application fee for each application my daughter sent to US universities.