Don't waste money on jewelry cleaners
Once you've got the perfect piece picked out, ask your salesperson to ring it up and just say no to add-on sales, especially jewelry cleaners. Retailers will charge anywhere from $5-$25 for a small bottle of purple liquid that's supposed to be just for gems. I'm not certain what's in those bottles, but I'll tell you what they're using in the store to clean their merchandise: Windex. Really.
A little watered-down Windex will safely clean most any jewelry, and you can just about buy a lifetime supply of Windex for the cost of one ounce of that purple stuff, whatever it is. There are some gemstones that you don't want to clean with any chemicals, though, because the stones are too delicate. For opals, pearls, apatite, and other soft or sensitive stones, simply use an old toothbrush and some warm, soapy water.
You're already spending a lot of money buying jewelry. Save yourself the extra $5 and go for Windex (or an equivalent store brand) instead of the expensive purple stuff.