The price of alumina is entirely dependent on grade and particle size. Happily, my process makes 3-5 micron size alumina, which is very saleable. The bottom price for so-called 'brown alumina is around €300/tone delivered EU. The top price for micron sized pharma grade is around €2000/tonne. Nano-alumina (which I also know how to make) is around €2000/kg.
The market price of 'smelter grade' white alumina is around €300/tonne, but that would be for 500 tons minimum. And interesting (but perhaps obvious) fact is that the market price of aluminates in general follows the virgin aluminium and scrap aluminium prices - they move together.
We have AFAIK no operational electro-smelter in the UK, and only a few gas re-smelters, so a lot of our scrap (and the UK creates 5% of the worlds scrap) is exported, but now the export markets are being shut down by governments - China, Vietnam, Malaysia even Bangla Desh, Pakistan, India are restricting imports so there's a huge mountain of scrap building up here and particularly in the USA.