You can buy your stock from a wholesaler and list them on your online Selz store for customers to purchase. You will need to describe the features of each product in detail, and, since headphones are something of a fashion statement, include photos. Because this product is in high demand, with the right prices and marketing, it should sell fairly easily.
Time to get scrappy! Start building it all out yourself with Wordpress or any other free software out there until you can get going and hire/partner with someone. Then you’ll not only have something to SHOW these guys, but it’ll also show *them* that you’re doing what it takes to make this vision of yours a reality and that you’re super passionate about it. Everyone has a million ideas out there and it would be awesome to have partners right fromt he start who believe in it and willing to jump in to build it for free/peanuts, but sadly it doesn’t usually work out that way. Gotta just get out there and start DOING IT and hack it together as you go… If it’s a good idea (and you’re truly passionate about it), you’ll find a way to make it work :)
The type of business that requires active owner participation at all hours of the day may not be the best if you’re working a full-time job. For example, if you open a service business and customers want to see you during daytime hours, you’ll be limited to only your lunch break. In addition, it’s typically a bad idea to take phone calls during your full-time job or communicate via email. The best type of side business is one where you can dictate your own hours. After all, you don’t want your side business to endanger your full-time job or vice versa.
As for other tips, all I can say is “a penny saved is a penny earned”. If you are running out of ideas to make money, start saving. Some quick “low hanging fruit” tips to save some quick cash include – switch to MetroPCS or Boost for cellphone (I only pay $20/month), switch auto insurance to Insurance Panda ($25/month), and start using GasBuddy (saves me like $100/month at least. I drive a lot).