That spec, with a decent case and PSU, would be nice for the price.
However, you're already seeing price-creep. £930 inc Windows, plus whatever they charge for a better case. And potentially a better PSU - (were they really saying a white-rated EVGA PSU, which is possibly as bargain-bucket as 'okay' goes adds £30 to the order?! They must have a great supply deal with Riotoro).
At which point you get to ~£1000 other companies start being a lot more competitive on price. For instance another UK custom builder:
https://www.pcspecialist.co.uk/saved-configurations/amd-am4-gen3-pc/0UWpXRdjdd/
If Palicomp would kindly confirm what Riotoro model it is - i.e. is it that okay Builder Edition one - that would help.
Only telling the customer a brand and (supposed) wattage is like saying "Buy this motor vehicle - it's by Ford and it has horsepower". Doesn't give much away...
In fairness a lot of companies do that for some components e.g. you get OEM branded SSDs that could be whatever. But an SSD will be hard pressed to fry your system if it goes wrong, unlike the part that is funnelling the electricity everywhere.
It's very possible they are using a Builder Edition, they just really ought to confirm it if so, or tell you the exact model so you can look it up