The legal term is diminution of value. A never-hit car with all its original panels is worth X amount of money. Once it gets hit, even after repair it is now worth X minus Y in value.
This is a legitimate claim to inquire about with the insurance company. I don't know your car's history but if this is the case you definitely need to raise the issue with them.
I dropped Hagerty years ago after they kept raising my rates year after year with no claims. I have been with MK Insurance for almost ten years now.
http://www.mkinsuranceagency.com/ Tamra Petro is the lady to talk to there. They even give a discount to car club members.
The real test of your coverage and the company is when you have a claim. I had a nick on the outer edge of the door on my Gramma's 75 Firebird several years ago. It happened when the door opened too fast and just barely hit the garage wall. We have owned this car since new. MK paid more than your Hagerty collision estimate to have the door nick repaired and they demanded that the 2/3 of the car be repainted to make sure it was blended properly (Lucerne Blue). I was amazed at how attentive they were. No questions asked/no hassles to the body shop. My body shop guy was equally amazed at their cooperation and attention to detail.