Instapaper offers a somewhat reduced pocket/pinboard premium experience for free since last November. Importing from pocket is very easy, I don't know about pinboard.

To avoid confusion: the premium level is the default level now...

From https://www.instapaper.com/premium: "Full-text search for all articles in your account"

Does pinboard archive it? Or do they make an API call to the Internet Archive and rely on that as the canonical version?