I shot mostly Trap along with some Sporting Clays & Skeet for about 8 years before the price of Shot went through the roof. Back then, magnum lead shot was $12 - $14 per 25# bag. There was myself and 3-4 of my friends that were shooting my reloads. We reloaded over 5000 rounds a year for the first 6 years and the last 2 years we reloaded 8000 rounds per year.
I started with a 12 ga. MEC 77 Sizemaster for a couple years but it became work so I invested in a MEC 9000G progressive. The Sizemaster would load about 300/hr. whereas the 9000G was double that amount at 600/hr.
A Sizemaster will cost about $250 in today's money. That would be my choice to start. Nothing wrong with the MEC 650 but I preferred the Collet Sizer.
http://www.natchezss.com/product.cfm?contentID=productDetail&prodID=ME812012&src=exrbSrch
I recommend buying the Adjustable Charge Bar & Powder Baffle. That will run about $45. This will save you money on the powder & shot bushings and allow for more precise adjustments. Easier to change powder types and shot size.
http://www.midwayusa.com/product/24...rogressive-shotshell-loaders-650-grabber-9000
Primers are about $50/1000
Wads are about $8/500 (I use Wind-Jammer Wads)
The last I heard, Shot was about $38 per 25# bag for lead. (Not sure about steel or other options.
I use Accurate N-100 powder that runs $16+ per 3/4# and $71 per 4#. (about 370 loads per pound)
http://www.midwayusa.com/product/2183153402/accurate-nitro-100-smokeless-powder
At my last calculation, it cost about $5 a box for Lead Trap Loads. Not a big savings considering the investment unless you shoot a lot. Savings might be greater if you're loading water fowl loads?????

Depends on the price of the shot???????
I still have the 77 Sizemaster and still load 12 ga. I've been shooting some Sporting Clays with a 20 ga. O/U and I buy my 20 ga. shells at Walmart, If that gives you any hint.
I hope this helps.