I joined Pinboard at a time when there was no recurring costs, just a small fee to join, for life. I think I paid $10 total, 12 or 15 years ago, and not a penny since. For that amount it's a pretty good deal.
(For those who don't know, the site moved to a subscription model in 2015 and I asked old-timers to consider converting their account voluntarily. Everyone who chose not to still has a lifetime membership to the site.)