votrechien - 9:31 pm on Oct 25, 2012 (gmt 0)
As mentioned, your best bet is to first try on eBay and/or Amazon (ebay being the easiest choice). There's no reason why you can't be on eBay and selling within a couple of days worth of work.
After credit card/PayPal fees along with eBay/Amazon fees, you're looking at paying approximately 20% of your gross sales in fees. If you have your own website you're going to pay somewhere around the same in advertising and maintenance. But I'm sure you pay for a table at the flea market so you're familiar with the fees for selling on market places :)
There's nothing wrong with selling things for $3 or $4 in profit. Dollar stores make fortunes with much smaller margins. And if you're net profit is 40% you're laughing. Most retail is around 5% (don't confuse gross with net margins though). The only danger when dealing with small profits like this though is that you actually are making far less than you believe when overhead and other things are taken into account.
But again, your best bet is to go on eBay and trying to sell immediately. Don't worry about questions like 'can I be profitable?' 'how profitable?' etc. right now. First see if there's demand online. If you can't sell anything on eBay, chances are you'll have a tough time selling anywhere else. If you can sell a few on eBay then there's a huge online universe awaiting you :)