I would not let anyone tell you what you should or should not like. Although, folks here know the watches, what is desirable to collectors, and things like availability of parts etc. It is clear you like yellow gold, which is cool. Are you interested in a metal bracelet (band), or would you be open to a wearing a leather or fabric strap. In your price range you will be looking at some sort of gold plate. Plating will eventually wear through, but some is better than others. Gold capped is usually the best. It is a heavy cap of gold over the top of the watch. You can recognize it because the back the the lugs won't be gold.
Your selection of watches include quartz, automatic, and a tuning fork movements (the insides that make the watch work). These each have their own features.
Quartz watches use batteries and really came into common use in the late seventies. They generally will be the most accurate, and require the least maintenance. They lack the intricate mechanics of the others, and are simple on the inside (see below). All else being equal, they should be the cheapest. The second hand will tick once per second, as it is turned by a little motor. Some of the early Omega quartz watches were cheaply made to compete with the Japanese companies. Notice the plastics.
The automatics are fully mechanical, and are powered by the motion of your arm. Each time you move the semi-circular pendulum winds a spring that powers the watch. There are lots intricate little gears on the inside, and complicated engineering that really excites watch nerds (see below). They don't require any batteries, but every 5 or so years they need a full service. I not sure about Australia, but I'll guess it costs $25-300 aud to get this done. The watchmaker completely disassembles the whole watch and cleans and inspects every part. The automatics are less accurate than the quartz and might find that the time is off by a minute after a week or two. It is easy to reset the time, but it might not be something you want to deal with. The automatics will very quietly tick 3 or 4 times per second and the hand move much more smoothly. The smooth sweep of the second hand is pretty cool, and I like to put my ear to the watch to listen.
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The tuning fork watch is a rare technology that was really only available for about 15 years. The watch is battery powered and has a little tuning fork on the inside that vibrates 300 times per second (see the 300 Hz) on the dial below. It is hard to find people to work on them but they are cool. I sent my from the US to Thailand where one of the most well-known tuning fork watchmakers lives (he is an Aussie). The tuning fork is probably not a good first watch, but they are cool.
Now you just need to decide if you are into the idea of an older mechanical watch (automatic), or a quartz watch.
