How did I miss this? Amazon slipped the entire Seinfeld into Prime Video, so anyone with Prime can stream the entire thing for free.
Is it a "deal"? Maybe not. But if you have Prime and you've seen Seinfeld you will thank me, and if you've not seen it yet, what are you waiting for?
If you don't have Prime, see if you can get a 30 day free trial to watch the show. You can always immediately cancel the automatic subscription payment. https://www.amazon.co.uk/dp/B01N9D23Z3/