Tickets are economically priced. Buses travel each way from the UK to Paris leaving every day.
Megabus Europe is a no frills, cheap journey, though it does take longer than flying or travelling on Eurostar. It takes around 8.5 hours from London Victoria to Paris Porte Maillot Coach Park. But at the prices they charge, customers generally don’t mind an extra couple of hours and a numb bum!
For more details and to book tickets see Megabus online