What is this bolleax about laptops being no good for FSX? I have a Toshiba Satellite Pro that runs it perfectly well. It may have a good graphics chip (for a lappy) but didn't break the bank, under £500 about 6 months ago. It runs Vista and all that I throw at it.
FSX isn't actually that demanding in graphics, memory is the main constraint.
These days you should be able to find something to fit the bill at about £350 or maybe under.
Good luck.