I've heard about developers giving their game on ps+ for free for the exposure they get, so I seriously doubt they would offer 500k and even consider paying 700k for an indie game. There is no way they are making enough money from subscriptions alone, especially since they don't get £40 for every one-year subscription. There are tons of deals that offer it for much cheaper, so they must be making less than that.
Also, if you read any comments from any site that announces the ps+ games, there are always tons of people complaining about "indie crap" and only praise the AAA games offered. Whenever there is a poll, people always choose the AAA game over indie. So, I see no reason for Sony to pay that much money, since I doubt they would convince anyone to buy ps+ for an indie game, while games like DMC and the latest Bioshock are a completely different story.
