Considering those are European models with the air dam, don't expect to find any for a reasonable price over here. I found one in really bad condition when searching and it was over $100...and needed a lot of work to ever make it right.
You might pick one up overseas for a reasonable price, but the shipping will cost as much (or more) than the part.
Also, they will only fit on A bodies like the '70 Dart shown without extensive modification to get them to fit a flat front bumper A body that doesn't have a valence under the bumper.