I use a Lee Load All for both my 12 & 20, I have'nt shot skeet or trap since '89, but still load for hunting, slug shooting & buckshot. I've had the Load All since '89 too, bought it from LeBarons for $27.99.
The smaller the gauge the more cost effective it will be. Lead is $42 a bag compared to $25 this time last year...
Something else to keep in mind is that not all loads are commercially available; trying to loads with get No.1 or No.2 shot are quite difficult for me, thus far.
I found No. 2 at Wal-Mart tonight. Check it out... I had to walk behind the counter to see them at the back of the glass cabinet, though. No one said anything about it. Buckshot 0, 00, and 000 I could not find, however.
Also helps to buy your components in bulk, keg of powder etc. Yes you do have the advantage of customization(3/4 oz 12ga. etc.)
Still looking for an Ontario supplier for reloading supplies, preferrably close to Toronto...