Keep checking websites and social network groups that look for price drops. There's a Facebook "like" page called "10 ways to have more money as a student without working" that posts amazing deals, and there's always hotukdeals.
If you're a PC gamer as well then it's always a good idea to check out green man gaming, cjs cd keys, steam sales, humble store (and bundles), you get the idea.
For console games then there's always your local small time businesses that will sell games at a fair price based on current market value if they're run by someone who knows what's they're doing.
There's also generic pawn shops like cash converters where they'll either be fair or they'll have no concept of what the game is worth thus either in the worst case scenario would make games over priced, but often will have under priced games too.
As for consoles, if you have a spare 2.5" sata hard drive laying around with a fairly decent amount of storage (such as enclosed within an external hard drive enclosure you have no use for), then you can purchase a 12GB PS3 super slim for £100 second hand and put your spare HDD into that. You can also acquire a Fat PS3 60GB for £105 used.
Xbox 360 is cheap if you go for the older model (£50 and up). Be sure at the very least you get the 60GB hard drive for it though, especially if you get GTAV.
Wii consoles sell for £30. 'nuff said.
Other money saver tips, never buy games at launch as the price drops within less than a month noticeably (especially sports games), Xbox 360 GOTY editions of games often come with a second disc with all the content and can be shared limitlessly, only buy special editions of games when necessary (i.e. really cool collectables or substantial DLC) or when the price difference is nominal. Buy DLC in bulk when possible, so GOTY editions for example. Steam also does DLC bundles occasionally at a reduced price.
There's also seasonal periods to get cheap deals. Summer sees a lot of used games traded in for people to spend on trips and stuff, which means used stores will get an excessive amount of stock that they will try to get rid of cheaply. Same applies to Xmas when people need money for gifts (such as new releases).
Oh and console games for 360/ps3/wii are at a low right now because of new consoles being out, but they will lower further once more games are released for them, and I'm talking the system sellers.
Unfortunately if you want the luxury of always having the newest released games and hardware, then you'll have to poney up the extra cash, but if you're willing to be patient and a bit behind and follow my advice then gaming on a budget is very achievable regardless of platform.
