I believe Microsoft and PS3 have a hand in pricing on their respective consoles.
This is true, but in the case of pretty much every game except Mass Effect 1/2/3, PS3 and 360 games always cost considerably more than PC games. This is because the commissions of Sony and Microsoft are built into the price. Brand new PC games tend to cost £30-£40 here in the UK for example, but PS3/360 games usually turn up at £50-£60. This is despite the PC version almost always being a better quality product* (rig dependent).
* 1080p / Highest quality / higher frame rates, etc.
I'm not sure about that one. I don't remember the last time I spent more than £39.99 on a PS3 game (these are brand new games I'm talking about rather than used or on sale). GTA V was £34.99 on a couple of sites if you pre-order. Although I did see Thief for £20ish for people who pre-ordered on PC as well.
@AngrySoldierSVK The DLC for ME2 and ME3 has recently been made available in bundles of €25 and €30 respectively. This is less that what you used to pay for the combined DLC.
I don't work for EA.