I have seen a used Wilier 101 that has a small dent on the horizontal tube. It seems that only some of the paint has chipped off and that there is no actual damage or crack. It looks as if a protective film has been lifted... Do you think I should have it checked out? Could an X-ray be done to see if the frame has been damaged? How much would it cost? I'm undecided about the purchase, but the price is very attractive.
Since the damage is not so obvious, it is probably not very serious.
Even in the worst-case scenario, i.e., that the damage is not limited to the paintwork but also affects the carbon fibers, it is likely to be easily repaired at a modest cost compared to the cost of the frame.
An ultrasound inspection is feasible, but it is quite expensive (more than the repair itself). In reality, a good diagnosis can be made with good photos of the damaged area, taken from different angles.