jwolthuis - 6:31 pm on Oct 20, 2012 (gmt 0)
Welcome to Webmaster World!
The products you sell at the flea market are $5-8. That doesn't necessarily mean that you must sell the online for $5-8.
You have the expense of a website, merchant account, packaging materials, maybe eBay seller costs, Paypal costs, postage account, etc.
When you sell online, your market is worldwide. You'll be shipping to Canada, Russia, Sweden, South Africa, etc; so it's safe to assume that none of your online customers have seen your products at your flea market. And you can set your prices differently.
Your gross profit is $3-4, or 30-60%. I'm assuming "gross" profit, because you probably aren't including your "wage" (a net profit of 30-60% would be Applesque).
I would calculate a wage for your hours worked, and target a net profit of 10-20%. Be sure to include the delivered cost of boxes, bubble wrap, advertising (Google AdWords), website costs, PayPal costs, and eBay seller fees.
Once you calculate your true costs, don't be surprised if your items sell for $10-12 online. (I'm just guessing here, but it'll likely be higher than what you're charging at the flea market).
If you include free shipping, keep in mind that residents of Alaska and Hawaii love that, and your costs may be significantly higher shipping outside of the lower-48. I'm not endorsing free shipping; I'm just saying that shipping costs can sink you, and you need to really watch out for that.
I hope this information helps.