Unfortunately its just the way it is, when a car gets to a certain age, they offset the purchase of aftermarket/second hand parts against the cost of new ones.

This has been happening in the automotive trade for years, and unfortunately the panel beaters have no say in the matter. Though I dont see how you can weasel your way out of second hand parts, if you're on the ball you will be able to save your car from after market parts.

I will add an additional note, not all panelbeaters will act the same way as a certain spray painter that advertises his services on here 'refer to a picture where two aftermarket fenders are fitted so poorly that it looks like a child did it', they can be sloted 'yeah I know', to fit exactly the same as replacement parts.

The Panel beating game has become really competitive (though due to the lack of accessable labour in the market now days has some what relaxed), there was a time where my father would lose insurance jobs due to a mear $10 discrepency in the quote, and only to have the customer 'whom most times was a life long repeat customer', come back with their tail between their legs siting what a shit job was done else where.

Other tactics insurance companies have undertaken:

-Making vehicles be tow'ed to their 'Care Centres', where repairers have to go out to the centre and quote on the spot like dogs; and
- Trying to inforce that repairers be able to quote on repair images sent by the insurance departments themselves and be liable for any missed damages (this of course didnt fly).

Good luck though, as I think everyone here has had a run in with their insurance company somewhere along the line.