When I say 2nd hand mountain bike I mean one I bought for £20, scratched up handlebars and frame, brakes that seem to brake (stop working) as often as they brake (stop)... amongst other problems. Ideal for short rides but any further than 10kish away from home and i would feel uncomfortable. If you saw it you would know what I mean. I would definitely rather buy a completely different bike.
I am confident I have enough money to fund this project and prepared to spend a bit of money on a bike, just want to keep it to a minimum. I've been looking at 2nd hand bikes on Gumtree and Youtube for around £300, figuring that way I could get a very good quality bike without paying a new price for it - I think some of the ones recommended to me in the shops were around £800!