Years ago I had the rear bumper painted on my Escort Cossie at a Ford Dealer.

It was £150+VAT which was 4 hours labour at £25 per hour and £50+VAT materials.

I couldnt argue with that and questioned why the labour rate was so cheap compared to workshop prices and the body shop manager said it was because the insurance companies force the rate down.

So with the cost of materials going up I dont think they are too far off the mark as I bet there is more than 4 hours in prepping the tailgate.