What's the cheapest way to travel from barcelona to monte carlo to paris to london? Planning my honeymoon help

I am trying to plan my honeymoon, please help! We are planning a 18 days trip.

depends when you are planning the trip, maby if you could get cheap flights from Spain to london with webstie such as easyjet.co.uk or jet2.co.uk ryanair.co.uk, and zoomairlines.com theses are the good websites that i use

Have you considered Euro-Rail? You can go by train from Spain to France to Monaco, and fly to London. Must you travel in that order? It would be more economical to fly to Monaco (Monte Carlo), travel by train (using Euro-Rail tickets) travel to France, then Spain. Fly or take a ferry to London (actually to the nearest ocean port ), then travel by train to London. Do not forget the Chunnel between France and England. Euro-Rail tickets must be purchased in the states. I do not remember the cost of train tickets. You can buy a block of tickets for a certain starting date perhaps two weeks. The Euror-Rail ticket does not work in England.