I will have training course in Luxembourg this May. And I’m thinking to travel to London during my free time. What is the cheapest way to travel from Luxembourg to London? May anyone gives me some suggestion on this.

I’m planning for a backpacking trip to western Europe (Austria, Belgium and Luxembourg, England, France, Germany, Ireland, Scotland, Switzerland, The Netherlands, Wales).How much cash do I need for backpacking trip to visit all these countries?
Hope you guys can suggest the cheapest transportation to travel around. Planning to stay 3-4 days in each countries.
Hope you guys can suggest the cheapest transportation to travel around. Planning to stay 3-4 days in each countries.