The Price for a GTI has dropped majorly in the last 12 months so £2300 seems like a good price to me.
Last year I paid £4000 for my GTI with 53,000 miles on the clock and that included all the extras (including leather heated seats). A good GTI is probably worth £3K now and maybe £500 more for an exceptional example.
You wont find many for sale in the 4K bracket because the reccesion has effected the value of all cars.
£2300 is cheaper than average but I wouldnt be put off because it's cheap.
Its had the cambelt done as well which is good

. The Gearbox is a problem on the GTI so make sure you ask the buyer if it has been replaced/refurbed during its time and if it hasn't then dont let it bother you.
Alot of people have problems around 50-80K miles but some people dont have any problems.
Si_GTI is on over 106,000 miles on his original gearbox so it shows that if the car is looked after then box can/will last
My car has done 61K on the original box and I havent had any problems whatsoever.
82,000 miles is about average mileage when buying a GTI so that fine, the engine is good for well over 150,000 if serviced on a regular basis
Ben