Re: How hard is casting?
Once you've cast a bunch of bullets they need to be lubed. Depending on the size of the bullet and the gun it's to be shot in, you can either simply tumble-lube using something like Lee Alox or use a luber/sizer that reduces the bullet o.d. to a specific size for loading and shooting. Many casters get good results with the tumble lube but I've found a luber/sizer to provide superior results for me. You can use a lube that is tailored to the particular gun and velocity. I use either Red Rooster or T/C blue which requires heat to allow it to flow through the luber/sizer. My rifle stuff gets lubed with my own recipe.
Personally I like cast iron molds over aluminum. They will certainly last much longer but are considerably more expensive. If you are just starting out you might use one of the aluminum jobs from Lee; especially if you are loading for pistol. They are also designed to be tumble lubed which is cheaper than acquiring a dedicated machine to lube and size.
Life's too short to shoot an ugly gun.....