You get what you pay for.
If you want the car to be lower than standard then cheap coilovers are fine, although how long they will last is another matter. It's likely they wont be made from non-corrosive materials and will therefore not allow for easy adjustment in the future.
If you want the car to maintain a decent level of comfort while being low and handling well, then you simply have to spend more money. My experience of cheap coilovers is that the ride is rock solid, crashy and not adjustable for damping.
In short, unless it's for cosmetic purposes only, save more money and buy better suspension.