From a quick look on eBay, you can pick up a vetinary ultrasound machine for between £800 and £2000. Are these materially different to medical ones, or is the cost difference down to certification?
Sources: asking the two vets I've brought birds to here, own visits to doctors
R&D and will be notably inferior with less capabilities than on high end systems, and you can probably also keep cost done if you skip some certifications.