Some food for thought:
"This is the saddest of all the many claims that those who want to leave Europe have made… The argument is: if we come out, we save 7 billion pounds a year. But, of course, it doesn’t work like that. There are two countries – Norway and Switzerland – who are not members of the European Union but have got trading agreements of the sort that we would have to renegotiate with Europe. And, if you actually look at what they pay for their trading agreements, it’s quite obvious that there would be very little saving, if any, for Britain, because we would have to agree as part of the new negotiations the cost of entry to that market.
But, you know, there is one fundamental difference. Norway, and Switzerland – although having access, and paying for that access – get told the conditions upon which their industrialists can trade. If we put ourselves in that position, we know that the French, Germans, Italians, Spanish, other industrial countries within the European Union, would set the rules, and they would tell us what we had to do. By being a member of the Single European Market, we help design the rules. So, A) We wouldn’t save any money. And B) We would be told what conditions would apply to us."
Would leaving the EU save Britain money? - Debating Europe