@irontoenail - I wouldn't start a side business like that unless I absolutely knew that there was going to be demand and that I was going to be able to handle it. You'd also have to know that you had enough capital available and plan to not make any money for a while.
Any kind of business that requires inventory is going to need a lot of start-up time and capital. If it's a side business, where you might not be able to give it 100% of your attention, then you need to be even more careful. You don't want to end up losing the family house on a gamble or anything like that.
You can start a business like that slowly, or you can figure out an idea that doesn't require inventory. Offering a service can be more rewarding anyway, as it's easier to pick your own hours and leave the business if you ever want to get out of it.