Nothing like an easy question to start the day!
There is no easy answer to your question Rose.
If you use sterling (or gold or gold filled) components in your designs and if you want to continue to work in that medium I think you just have to keep buying what you need as you need them. Customers at our trunk shows are wiping us out of Bali Silver because it was purchased and prices at something like $18 silver market. The shipment coming in will be priced based on $21 (or higher) silver market. It is probably a "good deal" to buy products that appear to be selling at a lower than current market...... but ONLY if you need and use that product.
Will silver drop in the near future? Maybe. How soon? Probably not very soon. Here's an article discussing the fact that silver has gone up 30% while gold only rose 19% in the same time. The article suggests that historically, when silver catches gold or even surpasses its rate of growth, it's a sign we've arrived near the end of the rally.
http://finance.fortune.cnn.com/2010/09/30/wheres-gold-headed-just-ask-silver/I fear we will see both silver and gold increase in price for several years before they drop in price.
What you
can do is take more care with the individual items you buy. Use lighter weight findings if they will work without compromising your design. If your work sells to high end customers you may not have as much problem as you would if you sell to lower end markets.
I hope I've helped a little? Perhaps other readers can join in with their take on this.