Ok - I started with a 1990 ZX10. Done roughly 100,000km, but the engine was still good. Would have been worth ,000 tops if I had sold it. From standard I have: Fitted Magnum cans - 0.00 - Very nice sound. Bit more performance, but mostly just the noise. Worth every penny. Fitted V&H Ignition Advancer - - Helped remove flat spot, and helped idling. Worth it. Fitted K&N Filter - - (I got 2 but I can't remember if the was each or for the pair.) Not much noticable difference, but lasts a lot longer than the normal filters. Worth it, but only really on a monetary value thing. Made the induction noise a bit nicer too, so that was good. Lowered forks by roughly 15mm. - </body> - This sharpened up the steering more than I thought it would. Very definately worth it. Braided Brake Lines - $Can't Remember - Worth every penny. MUCH better stopping power. Put in heavier weight (I think) fork oil - </body> - It was due for a change anyway. This has also helped out heaps. It doesn't dive anywhere near as much now. It handles much better on a smooth road, and gives much more feedback (this is both good and bad) on a bumpy road. Rejetting - 0 - This was the one I was most skeptical about, but I am very happy with it. So, the grand total: 60. I think I would be hard pushed to find a better bike for 60 with as much life left in it. (Cue people sending me links, trying to sell me their bike etc etc), and even if I could, I doubt VERY much that I would find one that would put a bigger grin on my face. And that, afterall, is what it's all about. I may not be that fast, and may not handle that well, but it feels fast, sounds nice, and keeps me with a big grin on my face. Still wish I could afford to put a turbo on it though.