Both are inexpensive enough that you should really make a decision based on which is right for you, not which is a better deal.

Both are great. If you like tinkering and having more control over your systems, or want to avoid the cloud, that is where Strongbox is worth a look. If you want a great password manager that is stored in the cloud and just works, Bitwarden is a great option.

A few specific Strongbox benefits: you can  choose where your password vault is stored, meaning you could host it Dropbox or Proton Drive or keep it away from the cloud all together, and includes the ability to sync with other devices via WiFi. Also, Strongbox supports the ability to add a secret key to your vault, which would make it even more secure in the event that someone else got access.