I have a 2000 YZ 250 w/ a Pro Circuit pipe and Boyesen Reed cage. The bike is real quick and I'm very happy with it but I know where I can get an IMMACULATE 2003 Yz450F for $3,700. I know the original owner and the bike has only been ridden about 10 times. My question is, does anyone think it would be worthwhile? Is there a noticeable power increase? I race some local hare scrambles, GP's and sometimes ride a motocross track here in Nevada. For those of you that have ridden both bikes what would you do? I've heard that the 4 strokes are VERY diffcult to start once you drop them.