David, although rodi is right, I think he takes his comments to the extreme sometimes.
People have to start somewhere, and generally they don't have the bankroll that
some people have. It's good to start with the basics, a decent camera, a macro lens, and some backdrops. You can use construction paper, fabric, etc for the backdrops. Play with different ones and test it out. That being said, I know lighting is of the utmost importance with macro photography, but I'm sure as you learn through practice and get better with your skills, the strobes will come in due time.
I say, be the best you can be with the equipment you've got. That way you can gauge what equipment you will want to upgrade to in the future (be it a better body, lens, strobes, pro models, etc).
Btw rodi, you don't
need models to shoot jewelry, unless you plan on showing them worn. There are many good sites showing jewelry on various pedestals, positioned in certain ways, etc without any models getting in the way.