In response to cadeau......Lyman molds will cost at least double what the Lee ones cost, RCBS and Saeco are more, they are made of iron not aluminum, they will last a long time if taken care of. Not all aluminum molds are bad however, NEI , Mountain Molds, LBT, all produce very good molds from aluminum, and i like using them as well. The aluminum they use is hard, much harder then the very soft Lees, NEI uses the same grade of aluminum that is used for making gears. Lee aluminum is so soft it galls when contacting similar metals, the screws are alum., the sprue plate is alum.The screws are the first to gall, making them "stuck" and any attempt to loosen or tighten them in that state will result in them snapping off.
I also have alot of brass molds from custom makers and they are very good to use as well. It's like the old adage, "you get what you pay for".