That £50m per day equates to £18.25bn (£18,250,000,000) per year. That's £300 per year for every man, woman and child in the UK just to pay to direct contributions. The extra costs associated with EU membership in terms of protectionist tariffs that make goods expensive, damaging environmental taxes, the burden of red tape that makes doing business expensive, etc. are on top of that.
Most of the population want to leave the EU, it is for the europhiles to make the case for continued membership. The single market doesn't require £50m per day membership of the EU so what do we get out of the EU that's worth £18.25bn per year? If the British government can't find anything then there's no excuse for keeping us in, wasting all that money.