That's seems unusually inexpensive for an Airedale. I wouldn't fool with a bargain-basement priced purebred.
Have you considered a rescue? Airedales are great dogs, but can be difficult to manage and aren't for the faint of heart. Many buy them because they like the look of one, only to realize they are no match for the airedale's intelligence and energy. Consequently, many end up homeless.
Of course, those dogs will be neutered, so if you're looking for a breeding sire, he wouldn't fit the bill but then breeding a pet quality dog, (with a pet quality price) wouldn't be the best for the breed either.