Hell, get an old cb350/450/550 honda street bike for cheap as hell on ebay. Insurance will be cheap, and it has already depriciated to the point you will probably get most of your money back when you sell it. Not the fastest things in the world, but plenty to get experiance and confidence built up. a 350 will see about 100 top end, and wont pick the front up if you get into it to much.