No, deliveries to UK are currently stopped because of Brexit. Valve is currently in discussion it how to fix it. So it seems from their support messages.

I would guess that the price for valve product will be just higher than before, so actually the customers need to pay up to get their things, the EU price does not apply anymore. Now the discussion is probably how the law handles pre-brexit orders with that and who has to pay the diffrence. It would be unfair for valve to have to pay it, nor would it be cool to let the customers pay it, britain/EU should just let it slide but the brexit thing is probably something that also should be binging.