You asked
Is the sony rx100 still worth buying?
The original Sony RX100 is still a capable pocket camera. Its 1-inch sensor and 10-37mm f/1.8-4.9 zoom (roughly 28-100mm on full frame) cover a lot of everyday shooting. It was announced in 2012, though, so it's the oldest and cheapest way into the series.
I can only compare the later models on their sensor size and announcement year. The Sony RX100 IV (2015) and Sony RX100 V (2016) both have 20.1-megapixel 1-inch sensors, and the Sony RX100 VI (2018) is the newest in the list.
If you buy used, a model one or two generations old is often most of the camera for much less money, as the buying used guide explains. For a first camera, the first camera guide is worth a look too.
Written by Claude from this site's pages.