I hit a curb while hydroplaning before (crappy stock michelin MXV4's, stock rims, stock suspension)...i was going about 15 mph by the time i hit the curb. $3,300 in damages. (really, just about $1,200 in parts&labor) apparently, the subframe was damaged, the whole driver-side suspension was reworked, new shocks, springs, arms, joints, etc.

if you have a hard hit vertically to your suspension, it won't cost too much. it's made for it. if you have a light hit horizontally, it will cost more than the hard hit vertically.

get your car aligned. they can tell if your caster is off. toe is correctable. camber is slightly adjustable, but for caster, you need to fix either the entire suspension, or get a camber kit and hope the ball joint doesn't slip.