Most has been covered here pretty well already. Reloading 9/8oz 12g has minimal savings (and there was a period a few years back it was actually more expensive than budget factory loads). Your shell cost seems a bit high- but there are a few components that you need. My estimated costs are $0.055 for powder, $0.06 for primer (wild card right now), $0.03 for wad and $0.16 for lead ($55/bag) or $0.30/shell plus tax. It really depends on the cost of the components. Loading down to 3/4 pulls $0.05 of lead out ($0.25/shell plus tax).
The real advantage for me is making special loads you can't buy easily. I load 3/4oz 12g for skeet and for beginners- very low recoil- my 10yr old daughter shoots them no problem. Also can load up special hunting loads which would otherwise be very expensive. I don't load 9/8oz at all- I shoot the cheapest factory shells I can buy.
If you want to get loading I'd suggest collecting primers and powder- both seem hard to come by at the moment. The lead and wads should be easy to find- but need to find good prices to keep costs down- definitely hit up old timers to see if they will part with some of their stash. I would also start collecting hulls. People do different strategies for hulls- you may need to figure out what works for your situation. Personally I tend to not mess with the cheap hulls- they aren't worth the trouble. Gun clubs are the only cheap hull worth reloading IMHO, but even then I am almost 100% AA hulls. I will load up cheap hulls when I know they won't come back (Uncle's hunting trip) but in volume the AA's have consistency and durability which I appreciate. I'm pretty lucky to have been able to collect an adequate supply of AA hulls over the years- but your situation may be different.
Not sure about all the hate on for challengers- I've cut a few apart and the shot looked great inside. But I guess everyone is entitled to their opinion. I will shoot them without a second thought. If the OP is just shooting 9/8oz target shells personally I'd be shooting the challengers from the club.