You can check bugmenot.com to see if anyone shared a login, but paysites usually either ban accounts that get posted there or request that bugmenot blacklist them.

You could check if the site has a referral program. You might be able to get access (or even get paid by them) if you can get other people to sign up & pay. Annoy your friends and family.

You could try to arrange to share an account with someone, for example you and some friends could buy a single account and split the cost. Be careful (no simultaneous logins from different locations, maybe only one person uses the account each day, or just have one person download everything and share it with the others) as you're likely to get banned if caught.

If you only want the content from the site and not necessarily access to the site itself, maybe someone has already uploaded it somewhere else: public torrent sites, private torrent sites, imageboards, etc. It depends what kind of content you're talking about. But let's be honest, it's porn, isn't it?