I'd second this, a (hefty) one-way charge is almost a given between taking a car out of Great Britain. Easyjet is absolutely fine for the hop between Scotland and Belfast. Easy operate to Belfast International (Aldergrove) which is 20 odd miles from the centre of Belfast, if your final destination is Belfast city centre, then Flybe to Belfast City Airport (3 mi to centre) is more convenient.

I wouldn't hesitate to take either Flybe or Easyjet on this journey.

A final option which hasn't been mentioned is Ulsterbus Cross Channel, there is a daily service from Edinburgh/Glasgow to Belfast travelling by coach and ferry. Not necessarily a fast service, taking approx 6 hours from Glasgow Buchanan Bus Station to Belfast. The fares are comprable to the cheaper easyjet/flybe fares (£25 per person single with advance booking, £27.50 without) and generally can be booked within a few days of travel if you need flexibility and include luggage. The fare also includes onward Bus or Rail travel to your final destination within Northern Ireland.

Info at: http://www.translink.co.uk/Documents...r%20201210.pdf