During company cost reduction, is it effective to implement paper-less policy without a server? Would it be enough to just save all files in PDF form especially for the Finance Dept?

Without a server or a storage media how can you store a large amount of data in PDF for finance Dept.

So it is better you have server to implement paper-less policy.

Probably it's possible to implement a paper-less policy without a server, but there should be a central storage kept secure to archive all the data.