Are 586 small block heads any good?

I do on the average of 10 swap meets a year,mostly Mopar only,so i keep pretty up to date on the prices of things. The LD340 and the LD4B are 2 intakes which I feel that the price has far exceeded the worth.I've seen people asking $250 for them and if they are selling them,more power to them. I like to price my stuff where it will leave my booth by the end of the show so what I think is a good price on stuff would probably be considered downright cheap by most people.I kind of like the pickers on TV,I have to get it cheap enough to turn it over.