I have done it a few times. (my interest comes and goes with this) You can get tin for about $6-7/# and clean lead for $1 give or take. You can get dirty lead for free if you sniff around.
The last lead I bought I picked up some used 8 oz net weights on Ebay and the guy shipped them in a box via USmail. The postal guy picked up a box and said..."gee whatyagot in here lead? and then dropped the box and it brust open in the PO 6-8 oz egg like sinkers rolled all over the PO floor

. The each box weighed #75. The PO has one box that is about 18" sq that is a flat rate shipping (like $12)regardless of weight. This pushed it to the limit.
I also bought some pure tin bars from a metal dealer in Denver. He will ship it to you. These are great for pouring tin jigs.
I had a few Molds I had made from vulcanized rubber. These are OK but not production quality. You get plenty of good pours from them.
Of course I have a slew of do-it molds and even a couple of old 1960 Herters molds that I got when I was a kid.
I also picked up a couple of real old orginal tin molds that have a pin like hook hanger. Someone had a ad in the bargin bin in the newspaper. I never look in that section but the one time I did I saw this and called him up. He had some more stuff too but we never hooked up after that.
I like throwing my own tins. I have caught plenty on them and get a kick when someone tells me how well they did with them. Also, if you loose one it is not big deal, reach in and pull out another. Also the properties of tin are better for most fishing IMO too:
A) slighlty ligher..you can through a larger jig without it weighing a ton
B) Sink rate is slower but still plenty fast enough.
C) natural shine to it.
D) Non-toxic to people and fish and environment.
E) can be recycled again and again
F) lower melting temp
G) Pours better
H) Eaiser to control the depth then lead in most places.
Don't have any photos off hand and have not made any original jig molds with my own design.
That said...there is a place for big lead jigs as well.