I'd buy. There are millions of foals out there already, most wasted. Why put another one into the world when there are plenty already on the ground of the same, if not better, quality than what your mares would produce?
If you don't want to take on someone else's problems - purchase a weanling. I purchased a weanling warmblood colt, he'd been just about untouched other than basic halter breaking, loading into a truck and taken to his Hanoverian inspection day.