Bros HELP ME , goin to buy a second hand bike. Rodeo a575 3 years old size : 27.5 21 gear , shifter shimano ... but rear deraileur was chnaged to SKILFUL (is that a good brand ?) frame seems okay.. handle got some rust seat is torn tyres are 80% used Disk brakes which work fine and.. the front suspension part can be shaked like it is cracked. the price they said is 8000 rupees. SHOULD I BUY??