A 30-30 could be a pretty good coyote gun, if you can hit what you're shooting at. It's not a very fast bullet, but has pretty good knock-down power.
It might be a good close range coyote gun but for anything more than about 50 yards you might want to get into the rifles.
Gun Parts Corp or Jack First websites
plenty
200
want ad, gun show, gun shop
50-200
If you mean the Mini-14, it will get the job done within its limitations.
Gun Coyote - 2012 was released on: USA: 9 December 2012 (Santa Fe International Film Festival)
100-1000 USD or so
.22 Magnum is my fave...
Blue Book of Gun Values
See: http://www.gun-data.com/tour7.html this may help you.