Socialism is not wealth redistribution but control of various industries in the economy, usually infrastructure to benefit the good of the people.
http://www.ukpublicspending.co.uk/uk_national_debt
Here is a graph showing British debt. Socialism came in after worldwar II when Britain was most in debt. If socialism cost money then how did we repay the debt? It ends during the 80s under Margaret Thatcher. You may notice that when it ends the debt starts growing again.
Socialism enabled the country to give all manufacturing contracts for oil, electricity, gas, rail etc to British based companies. This enabled mass employment at no cost to the the tax payer. It also enabled a very low unemployment rate and more money in the economy.