A friend who is a great enthusiast for VAG cars, has had several spring breakages on his and other cars in the family.
Apparently Japanese cars are less prone to breaking coil springs. Reputedly, this because the end coils are ground flat, (known as scragging? )so that the spring is not subjected to bending loads, just axial.
Our Renault 5s covered nearly 120K miles, each, without problems, but the spring seats were pressed to match the angle of the end coils of the springs, again, not subjecting the spring to bending loads.
A coil spring is really a very long torsion bar, so bending it increases the load to which it is subjected, probably beyond the fatigue limit, hence the breakages.
But if they survive out of warranty, look at the after market business sales and the work for the dealerships!
Howard