It costs f**k all haha, the most expensive trials bike you could possibly build would cost about £2k tops. Try riding XC or downhill! My new Simtra buils has cost me about £800 is total, including buying the Kot last year, so I've got a frame to sell now. It makes a huge difference having a lighter bike, not barely any difference. I rode Danny Kearns barge next to my Kot, it was so much more effort to move around and I got tired a lot faster. Lighter bikes just feel nicer to ride, and for the sake of a grand or so it's not actually an expensive hobby. (Compared to road, XC, downhill, dirt jumping, motorbike trials, motocross etc).