FM really isn't that 'greedy' with resources. If the laptop is solely to play Football Manager, you can pick one up from Argos, Tesco, Currys / PC World for less than £200. I've just had a look around and you won't have any problems with your budget.
Minimum system req's:
•OS: Windows XP, Vista, 7, 8
•Processor: Intel Pentium 4, Intel Core, AMD Athlon XP: 1.6GHz+ V/7/8: 2.2GHz+
•Memory: 1 GB RAM
•Graphics: NVidia GeForce FX 5900 Ultra, ATI Radeon 9800, Intel GMA X3100 - 128MB VRAM
•DirectX: Version 9.0c
•Hard Drive: 3 GB available space
As always, you get what you pay for though if it's being used for anything else.
One tip is to buy on-line. Not only do you get to see far more options without someone breathing over you but e.g.
HP 15-g093sa 15.6" Laptop
•AMD A4-6210 APU
•Windows 8.1
•Memory: 4 GB
•Hard drive: 1 TB
•Graphics: AMD Radeon R3
...from PC World costs £249.99 on-line and £349.99 in-store.
Ryan1990, PCspecalst rocks. V. good forums to ask for advice check your build. "Always spend £5 for the silver warranty". I got rig from there 2 machines ago - ended up wrong side of £1300.