They meter your agreements
As of their published pricing, DocuSign's entry plan is an annual commitment of $132 for five envelopes a month, and their $30/user/month plan allows 100 envelopes per user per year. PandaDoc's paid plans start at $19 per seat per month, per person.
You end up rationing your own contracts and doing mental math before you send a document. That's a strange thing to feel about running your business.