I have Mec 600 Jr/Mark 5s in 28, 20, 12, and 10 gauge. If one
doesn't count one's time, reloading shot shells will save
money, provided one finds deals on components(join a trap
club).
But the real advantages to shot shell loading is your favorite
loads are always available, and anything the factory doesn't
make, you can. I buy factory ammo in two situations. One - I
need fresh hulls, or two - I get a discount deal, so hand
loading doesn't save money. I duck hunt, and steel shot is
hard to justify hand loading, when deals are out there. I do
re-use the steel shot hulls, for tungsten alloy hand loads,
and there one can save a decent amount. And for me, shooting
a 10 ga., tungsten alloy loads are hard to find, and those
factory offerings are an insult to 10 gauges.
I find pulling the lever on loaders therapeutic, so there
is an added advantage for me. We have long winters, and
by Spring, I have big storage boxes full of shotgun ammo,
for the Summer trap season, and the Fall hunting seasons.
If you can find the coyote ammo you want to shoot, in factory
offerings, and you shoot 40-50 rounds a year, shot shell
hand loading won't save you money. Just shop for sales and
stock up. But if any of the other reasons, stated above, fit
your situation, by all means get into shot shell loading...It
is addictive. 
Squeeze