3d printer filament costs $20/pound. That's more then junkyard price for any plastic interior part. Yes they will ship, but that will cost more.
Granting the junkyard part will be old and brittle. Almost as brittle as the 3d printed part.
My car is a 24 year old Fairlady. The majority of these have been wrecked and/or dismantled, and altho there are some replacement parts available from both the original manufacturer and 3rd-party aftermarket parts manufacturers (mostly on the other side of the world from me) the used parts supply in my country is a dwindling resource. The wreckers here know that and pump up their prices to somewhere just a little below the cost of getting the part shipped here.
The cost of printer filament is probably still a lot lower, and also the time and effort put into this is a labour of love, rather than an attempt to sell for profit.