Ds (11) saw them yesterday in B &M for £20 and said they would be good for his main present. They were Goodmans and look a bit like lava lamps and I suppose they light up and glitter moves around when they're in use? The ones he liked were rose gold and you get 2. They're currently on Ebay for £40 but no reviews that I can see. Obviously for £20 my expectations aren't high but he loves his music and currently uses his Alexa as a speaker, so would want the sound quality to be comparable to that and I would hope the glitter was... I don't know, glittery and not a complete damp squid. I also would want it to last more than a couple of weeks.
For a main gift I would usually spend a fair bit more than £20 and there's nothing major he wants or needs this year, so we're looking at more small/medium gifts instead so if anyone has a recommendation for anything similar but pricier that would be good too.