just be a bit wary of buying an older bike that hasn't been ridden at all. that '99 750 dark with only 35 miles will need new tires (flat spots and dry rot) and a carb cleaning to say the least-- which if you're not into doing yourself could be three hundred plus in tires and service costs.
hope you find a good one! be patient, i was and found a great bike, don't be afraid of higher mileage if the service history is there and be prepared for the fact that you won't ever want to sell it! ask us any questions as we're all addicted to the same drug and love finding new members