Recently bought a 2nd hand DC5, it's been having a very tough time over bumps and potholes. So i took it into Pedders for a quick check up. The technican told me that the previous owner has put King Springs on the car and the reasoning why i keep hitting the bottom of the car is because the springs are too weak (is this true?) and in a true salesman's style went ahead to try and sell me Sports Ryder suspension kit ($650 all up). I have two questions

(1) Is that true about the "weak" King springs
(2) Is that the reason i keeping hitting the road when i go over bumps (even really small dips)
(3) What recommendations (for new springs) would you guys suggest for a low but not as harsh a ride (when a similar budget)