£350 will get you a reliable washing machine, just……….You will not get a ‘reliable’ washer/dryer unless you venture into mid to high Bosch/Seimens range, and even they have their limitations as do all washer/dryers.
If you could just find somewhere for a small dryer, even if you have to move it to use it, would be worth it because wash dryers as a rule, arn’t much good. And very expensive.