Bulgarians and Romanians were last night preparing to travel to Britain as restrictions on working here are lifted tomorrow. Almost all flights from Romania to England are full – even though one airline doubled the number to meet demand – with one-way tickets selling for up to £3,000 each. And all tickets for seats on buses leaving the Bulgarian capital of Sofia until January 9 have been snapped up. Wizz Air, the low cost airline that serves Eastern Europe, has doubled the number of flights it is offering. However, because of the demand, even these no-frills flights are being sold at around