Antminer S19J Pro for less than £1000

Is this a solid deal? I hear they’re supposed to be brand new. Shipping from China to the UK means adding 20% tax and additional fees. So it’ll cost around 1200 total for one unit.

Yes, it's a good deal but We don't know if it's new you are dealing with an unknown seller there is a big chance that the seller is a scammer or you will receive a unit with some issues. So it's risky to deal with them unless you buy it directly from Bitmain. If you want a cheap units with near or same hash rate speed then check Canaan units they are still selling cheap units like a1246-96T you can check them here below - https://shop.canaan.io/

Its through amazon marketplace so there's the amazon buyer guarantee I would go with Canaan but even with their sales its still expensive compared to bitmain

Did you check carefully the price of units from Canaan? I think you didn't check carefully the price from Bitmain and Canaan Shop unless you talking about 3rd party shops like amazon? We talking about the price of their units directly to the manufacturer's price between Canaan and Bitmain Shop you should see a big difference.

The canaan are less efficient and cost more bitmain s19 pro $1950 100T 2950W Avalon Miner A1246 $1728 96T 3420W or Avalon Miner A1346 $2461 107T 3300W bitmain is better option