How much does a full-blooded wagyu cost?

Depends where you live and how common Wagyu cattle are in your area. Usually the less common the breed, the more expensive it can be. Wagyu may be cheaper in Japan than in America, for instance. Also, it depends on what a Wagyu producer will sell their animals for, and what gender/sex you are looking to purchase. As such, no exact number nor even a ball-park estimate can be written on here. It is best to contact a few Wagyu breeders near you to see if they're selling what you're looking for and what their asking price would be.