This is something all publishers grapple with so I'm not going to fault Andrew for exploring ways he can make money for his time investment which is substantial. I think the pricing is a bit high ... I'd be more likely to pay $100/year for a subscription but I'm not sure if there's enough value in these interviews to warrant more. There might be but I'll have to think about it.
I also think it's going to prevent new users from discovering the value of the site and returning/becoming fans. Yes, you can watch one or two recent videos for free (currently doesn't work?), but I think people become fans when they can dig into the archive and watch some other interviews. I became a fan after discovering a link to a video somewhere and then spending a few hours digging through the archive. I'm not sure people who are just discovering Mixergy will get out the wallet on the strength of one or two videos, so they'll be less likely to dig deep and find the value of site. I wouldn't have done that, and probably wouldn't have returned except for the occasional link that shows up in a stream somewhere.
It's a tight rope to walk. There are a ton of monetization options he can explore and I don't blame him from trying. Just hope he doesn't put off his audience/guests or lose his momentum while trying to find the right path forward because this is probably the hardest one to sell.