I've had a look, not purchased, but watched a lot of review videos and I'd recommend you to do the same as no one here is going to have really tried all the different models available.
Unfortunately, the price does seem to correlate with the quality and performance and the most expensive auto vacuums cost in the £300 region. They also will never be as powerful as a traditional upright, can't do stairs and of course you still have to empty them and take them up and down the stairs to do the different floors of your house. But yh, the price is the biggest reason I've not gotten one myself.
I had Neatos for years. They worked great until they didn't; I always had to do a lot of troubleshooting. Now I have a Wyze vacuum, which I think is a rebrand of a larger Chinese brand. It doesn't clean as well as the Neatos, but it's had no problems so far, and it was much cheaper.
There's plenty of reviews out there if you want to get into it, and it does seem like some of the more expensive ones out there have some really nice features. But if you've been on the fence for a while my advice is to pick a well reviewed affordable one and go for it.
Once you have something cleaning your floors you'll have more time to research which one is the ultimate vacuum.
I have a Roomba j7+ and I love it. I also have a Braava Jet M6, so mopping is taken care of too. The mopping is slow, but it's quiet and it's not like I have to wait for it.
These free up so much time. Love mine too. I cook a lot and mess around a lot in the open kitchen/living room area and had to sweep the floor daily..not anymore.