Our pregnancy ultrasound is in the $40-$50 range. Honestly if you can spay a dog for that price either it's not being done properly with all the monitoring that a dog, especially a HW+ dog, needs, or it's some kind of charity that is funding most of it (or both). The latter I don't have a problem with, the former I do. Given all the problems that can pop up in a HW+ dog, monitoring is necessary.