You didn't say what type of lead you were looking for. If you want dead soft lead, then you can probably find it in ingots at a
plumbing supply house or even some
hardware stores. If you want antimonyal hard lead in ingots, then you will need to buy them from a metal supply house like rotometals.
I've always bought my lead as scrap, then smelted & cast it myself. It's not that hard, but you do need to take a few precautions to handle it safely & you do need a little
equipment. My basic rig was a
turkey fryer, an old dutch over from a thrift store, & a soup ladle.
The spot
price of lead has been hovering around a buck per pound for several years now. It's not
cheap like it used to be. Expect to pay at least 20% above spot +
shipping for retail on rough pigs.
Kitco - Spot Lead Historical Charts and Graphs - Lead charts - Industrial metals
If you need to get it shipped, then flat rate boxes from the post office are the best value for people in the US when dealing with quantities that don't justify truck freight. I've gotten 40 pounds into a medium flat rate box before.