Well actually this particular model of CB650 is "Air and Oil cooled".
Yes a liquid cooled engine is a completely different machine. You may find Hornet, Bandits, CBRs, FZR, Ninjas......they all are liquid cooled and 4 cylinders ......... a good one is hard to find but will fall under the posters budget.
All I meant to say is........ you dont buy Heavy bike for everyday use.....you use it once in a while.......for that its better to get the real deal rather than playing safe with a GS500.....which by the way is not that easy to maintain......spares issue hotay hain GS500 kay....and spares arent cheap....atleast not in khi.