It isn't similar at all.
Even if you want to ignore the selection, the distribution and therefore the costs are different because the services are different.
The EA agreement allows you download and play those games from the library. PSnow is a streaming service. The cost to maintain a streaming product is higher because the end user is not downloading any extra files nor are they actually processing the game content. That takes hardware on the service provider end to take care of while EA doesn't have to worry about an issue like that.
Another point in how they are "not" similar is that even in Beta PSnow works across multiple devices. EA Access currently does not. So in terms of how the services work themselves and the actual target audience, they are different and trying to compare the two is making a very large leap completely ignoring the technical differences between the two. Also if the publishers are setting the prices for specific titles then there is nothing Sony can really do about that.
Edit: Unless I am missing something but the wording on EA states downloading not streaming.
http://www.ea.com/eaaccess/faq.html
Thanks I just caught that.