Yes you are saying right its not possible to sell jewelry at low cost. I agree with you.
I feel you, especially when your store is online-based. Some competition just drop prices to the point that you can't keep up. Unless you can magically find a way to get materials half their usual cost, it's quite impossible to drop prices without sacrificing quality.
Anyhow, you should price the materials based on how much they cost today. Give your potential customer a reason to pick you over the other, cheaper handcrafted jewelry store - like better quality.
I usually use a 1.5 to 2 multiplier to set my base price plus a bit more for my labor if the piece can command it. Jewelry's in great supply and the competition is tough; there are over 3.5 million pieces listed on Etsy alone.
Have something different, original and keep the workmanship quality up to help separate you from much of the competition.
Well I think when you are realizing the fact that 30 US dollar is too low then you must be considering this as how low is this? And accordingly price your pieces. Other than the prices included for the materials used and employers involved (if any), what you really need to think upon is how much will you price your efforts.
Just a little thought on pricing, the US just signed a bill with a tax rate for a single person of $400,000. and over to a higher tax rate.
Now looking at this @$400,000. and divide by 52 weeks you get $7,692.00 a week, then divide by 5 days a week and you get approx. $38.46 an hour.
That doesn't even include and of your tools and matls. for the project. Not saying that you have to price your tems this way, but it does make you think about how and what to charge.