I researched the difference and apparently the only real difference is the temperature fluctuation allowed. Household irons will fluctuate like 30 degrees IIRC and snowsports irons are like 15. As long as you pay attention and don't burn up the wax, I don't see any issues with a household iron.
I'm just a noob though. I didn't want to pay $20 to wax a board so I learned how to do it even though I have only been snowboarding twice. I decided to get a Dakine iron because I like having "the right tool for the job" I like that they are small and light as well. The money that I saved by waxing my gf and my board, paid for my iron. It was on sale at our local sporting goods store. Next time I wax will cover all the other misc expenses (wax, brush, etc). Everytime after, I will be saving money.