At a recent Gun Show I saw reloaders selling their reloaded ammo, but I could buy the same ammo (at least for 9mm, I didn't check the rest) cheaper at WalMart. They're trying to make a buck... or six. :/
Are reloaded rounds even slightly less reliable? They can be... hand-reloading is done by man and not machine, the risk increases. Would you trust someone else's reloads, or just your own? As a general rule: No, only my own.
I've read that you don't want to reuse the same brass too many times, as it can split after too many firings. True. How many is too many? That's dependent on quality of the brass, the pressures involved and treatment of the brass by the weapons and reloader.
As a slight aside, in the Fallout 3 video game set in a post-apocalyptic world where ammo is no longer being manufactured (much), the option to reload your own ammo exists; I never found it necessary. Maybe if I was playing in an ultra-hard mode new ammo might be more scarce. No idea what you're talking about...
I think reloading is something I'd consider if I intend to fire off a large number of rounds, or if I were using large or hard to find calibers where individual rounds are pricey. For the amount I'm shootng, it'd take too long to recoup my investment. Then there you go, you've figured out it isn't in your best interest.