IDPA does have a lower round count, but realistically you can shoot either without reloading - particularly if you're just doing a local club match per month. Depending on which match I go to, I tend to shoot 100 to 150 rounds at a local match. In factory ammo, that's about $40. As a monthly cost, that isn't bad.
That said, handloading does certainly help out if you can take that step. I typically just grab extra brass left at a local public range so my bras costs are nothing.
Most reloads are about 5gr of powder, so a 1lb can of powder (about $20) will do 1400 rounds.
Lead bullets run about $60/1000, FMJ about $80/1000. Primers run about $30/1000.
So total cost for me would be $15 for 150 rounds of lead or $19 for FMJ. Over a 50% savings.
NOTE: All that is for 9mm prices, and 9mm is one of the cheapest factory rounds there is (and its still worth it for me). If you shoot .40S&W or .45 ACP you'll see a MUCH higher savings.