Why only focusing on ps3 niche. Try to target more broader market such as pc and xbox market coz this will diversity your income.Start up cost can be minimize if you using wordpress to run it.And then only change to custom script when you making money.You can be game affiliate to earn more money.
Games are good, and Playstation 3 offers some good affiliate programs (you could advertise games, but also consoles). So... sounds good. Of course there will be competition but ... that's like the situation everywhere. If you like playstation 3, like to play & write - then this sounds like a good niche. Good luck. Well, you can pick some wordpress theme for starters and worry the theme later. Most important is to get stuff written, graphics can come later.
if they would not work, there won't be any game cheats/reviews sites whatsoever. Check gamespot.com for guidance, that is the largest website related. See how they monetize, etc..
It is a saturated market, so one thing you could do is to go for the more longtail keywords and specific games. You could also try adding an Amazon store as an affiliate program or maybe sign up to the eBay partner network?
In my opinion unless you want heavy loads of work to do. E.G. constant updating of the site I wouldn't bother, there are already hundreds of sites out there that are almost like game media company's. In would be very hard to make a decent 'side income' from this market. But, good luck to you if you're really interested still in it.
Why would people want to buy GTA if they're looking up cheats for it, surely they must already have it?
I have to agree with the others that say that it is a heavily saturated niche, with big players that have huge wallets. Another video game blog is just that....just another video game blog. Unless you can bring a unique perspective, which will be hard since the major sites with all the traffic and authority actually are part of larger companies that make the games, it will difficult to make any money. Every kid that plays video games and learned how to make a blog, has a video game blog. I have never seen one that is different from the rest, including my own. I am speaking from experience, I got the blog, the site selling consoles, affiliate with ebay and Amazon, blah, blah, blah...the market is completely saturated. Trust me. If you are going to compete, you are going to have to spend some money, and I don't mean $100 in you adwords account, real money....unless you build a community around a certain game, or type of game, and that takes full time work. JMO