My 45 ammo costs are barely more than my 9mm. Then again I cast and reload my own , so...
That helps, lol. I don't reload, so I'm stuck with what the manufacturers make me pay. On sale, I can get a box of 50 9mm for about $10. .45 on sale goes for right around $19-20 for 50. Assuming no sales, the prices go to about $13 and $25, respectively (and we're talking Blazer steel case here).
I've thought about reloading. Right now, unfortunately, I just don't have the room to do it. Eventually, when I get out of the place I'm living now and get my own place, I'll seriously consider putting in a reloading bench.