Hi Jaxon
I'm realatively new to fossicking myself. Please someone correct me if I'm wrong. Gem stones (Quartz and Rubies) predominently are not metal so any metal detector is useless for them. Gold is a metal and can be detected by metal detectors. Depending on your location and where you wish to do your metal detecting different detectors perform better than others. That said I'm not aware of any detectors that are in your price range that do a good job for gold. If you add a zero to your numbers IE 1000 to 3000 you are starting to see some that might be suitable for your needs.
My suggestion would be to maybe join a club or do some research on exactly what you want to chase and where. A good gold pan and a set of sieves might be a place to start depending on where you are looking for your gemstones after you have done some research.
Bear