Buying 8lb kegs of powder, loading cast bullets lubed and /w gas checks, buying primers by the 1000, it costs me about 10 bucks after taxes for 50 rounds of .303 british. This is using 40 grains of BL-C(2) powder, not a light plinking load. I decrease my costs even more by using 5744 (30 grains, $850/50) for full power loads, or 700x (12 grains, $6.50) for light plinkers that my kid shoots. Figuring with this, you save about 25 dollars per box of 20 over factory ammo.
Think a press, dies, tumbler and stuff costs too much to recoup? You can set yourself up with a used single stage press, tumbles, dies, powder measure, bullet mould, case prep stuff for $300 bucks. Your costs are thereby mitigated after shooting about 300 rounds of home rolled ammo. You can't count your time, because you don't get paid to sit on your butt watching TV. You reload in your SPARE time, you don't take the day off work to reload.