What do you plan on doing with it? Do you have any other cameras?
I have an RX10 III that I could sell, or keep. I do like the range. I was looking at the e-m10 III and the nightscape long exposure stuff looks really cool which is basically the only thing the rx10 iii isn't very good at. If I sold it it seems like I'd be losing some IQ and about 350mm of range. Looking at dpreview studio comparison and lots of samples the rx10 iii seems to surprisingly have better IQ. Looks better than aps-c canon honestly too. Loses to Fuji by a bit but not by much. The Fuji glass is just way too expensive, as is ff Sony.