I didnt do radiographs when I PPE’d my 4 figure purchased horse. About a year later he had an issue and the xrays showed some “irregularity”. The difficulty was that we couldn’t tell if it was significant to the lameness or if something he had had for a while. Eventually did MRI that showed soft tissue injury. That healed after rehab. Radiographs taken two years later for shoeing showed no additional bony changes.
If I were to buy a horse again, I would want some screening pictures as a baseline. But I also wouldn’t freak out and dismiss an older sound horse with some changes.