Yes, your syntax is incorrect. The OpenBSD project has all mirrors use the same folder structure.
One way to verify your mirror and pull the path is to use the built-in
ftp(1) client in a terminal. Use the
cd (change directory command) command to change to the desired package directory. The
pwd (present working directory command) will echo the path to the packages working directory. This can be copy'd n pasted into the PKG_PATH declaration in your
`/.profile
Also see this example at
M:tier.