What Derek said really, the extra £150 is worth it for the 'extras' you get. Everything in the kit is relevant & you'll use all of it some of the time. As regards a laptop, the Picoscope is not very 'computer hungry', believe it or not it will actually run on an old 486 machine, but I would advise something a little faster, as you might want to have several windows open at once. I'd suggest that you find a second hand laptop with at least a 20Gb hard drive, 128Mb RAM & at least a 1Ghz processor, This will give you some scope (sorry pun not intended) for the future, this would also allow for a KTS or similar to run on it. Make sure it is equipped with a Parallel (Printer) port (some recent laptops don't have them due to proliferation of USB) as the printer port is used for Picoscope. USB is also normal & required by other equipment. However there is a USB to parallel adaptor for Picopscope available for £50 if you need it.
If you need any more info, please let me know.
Regards, Rob Drinkwater. Business Development Manager - CAFTEC Division. Camberley Auto Factors Ltd.