Campaigners for and against UK membership of the EU have debated the better option for people in Wales.
Leave.EU chief executive Liz Bilney claimed it cost £55m daily, which could be spent on schools and hospitals.
AM Eluned Parrott, speaking for Britain Stronger in Europe, hailed cheaper and more secure food supplies.
With a referendum called for 23 June, three of the Tories' 11 Welsh MPs have said they want the UK to leave, while all 25 Welsh Labour MPs want to remain.
David Cameron confirmed the date of the vote after negotiating a deal in Brussels which gives the UK the right to restrict EU migrants' benefits and to be excused from taking part in "ever-closer union".
Debating the arguments on the BBC's Sunday Politics Wales programme, both Ms Bilney and Ms Parrott claimed the terms of trade would be better under their preferred option.
Ms Bilney said the UK would be free to negotiate its own trade deals outside the EU, while the Lib Dem AM said there was a benefit from being part of the world's biggest single market.
Ms Parrott also pointed to the EU as a force for peace over 60 years, while Ms Bilney said the UK's membership of Nato, the UN security council and friendship with the USA provided security.
Elsewhere, deputy Labour leader Tom Watson told the party's Welsh conference in Llandudno that the UK would remain in the EU but winning the referendum would not be easy.
"The Tories could end up destroying themselves over Europe but we won't let them destroy our country", he said.
Monmouth Tory MP David Davies told BBC Wales that he would be "campaigning hard" for the UK to leave the EU, describing Mr Watson's view as "wishful thinking".
He said the Conservative Party would be united irrespective of the referendum result - but he hoped the result would mean the UK was no longer part of the EU.
Mr Davies is one of three of the 11 Welsh Tory MPs who have said they will vote for Britain to leave the EU - former Welsh Secretary David Jones and Brecon and Radnorshire MP Chris Davies are the others.
Five have declared in favour of remaining in the EU - Welsh Secretary Stephen Crabb, Guto Bebb, Byron Davies, Simon Hart and Craig Williams.
Three have yet to declare their view - junior Wales Office Minister Alun Cairns, Glyn Davies and James Davies.
Plaid Cymru confirmed that the party and its three MPs would be campaigning to stay in the EU.
"We have to see the big picture," said Euro-MP Jill Evans.
"There is a lot we would like to change about the EU, but we can only do that from within. The decision we make is about the kind of Wales we want to build and will affect generations to come."
Analysis by Arwyn Jones, BBC Wales political correspondent
Wales is slightly different to the rest of the UK. Areas like west Wales and the valleys get hundreds of millions of pounds in EU aid, far more than any other part of the UK.
Between 2014 and 2020 that is going to be worth £2bn.
Farmers here share in another £200m of EU payments a year, which could be lost if the UK opts to leave.
However, those who want to leave the EU say it is not "European" money, but our money.
They insist the money could still go to poorer areas of Wales - it would just come from the Welsh government rather than Brussels.
However, we have yet to see any concrete plans that the UK government would be willing to send additional money to Wales in the event of Brexit.