lots of them on ebay... prepare to spend some $$$. I got into it a couple years back and ended up selling off all my molds and lead because it was so expensive for all the supplies. The DO-IT sinker molds are probably the best brand.
That's why I posted here... trying to find something inexpensive. I acquired about 90lbs of lead for almost nothing, and wanted to make some jigs and surf sinkers. If it is going to cost more than just buying the gear at the store though, might as well take the lead to the scrap yard.
Once you got everything it's cheaper to DIY. the start up cost is what's high depending on what lead melting pot you go with. you can keep it cheap with an old pot and ladle or get the bottom pour melting pot. The molds are about $40 each new but you'll need a few different style. The lead is really the expensive part.
It depends on how much you fish. If you fish a lot and go through a ton of weights you'll save a ton molding your own instead of 30 & 40 cents an ounce from tackle shops. If you don't fish a lot then the cost will probably never pay for itself.
If you have a source for lead and you fish where you use alot of weight like surf fishing for instance, there is no question that it's cheaper to buy molds and a pot than to store buy weights. I don't have a fancy pot. I just have a cast iron pot with a ladle which is exactly what you want casting fishing weights of any size. The fancy little hand pull jobs are made for bullet casting. Not pouring weights that weigh 3+ounces. Two of us can mold 50 pounds of no rolls in a couple of hours. Enough to last a couple of years of hard surf fishing.
Another thing with molding your own. You can melt down what you have and recast it.
I have a friend that metal detects. When he gets a 5 gallon bucket of sinkers off the beach I pick them up. Recast them.
I always buy new. Most molds aren't that expensive. 35 bucks or under. I buy mine from Barlow's tackle. Seriously thinking about buying one to make my own pulley rig weights. Available out of England for around 76 bucks. And then you have to bulk buy all the parts to go on the molded lead.
Just start out with one style, later on progress to other molds.