Foreign Secretary William Hague and Chief Secretary to the Treasury Danny Alexander said it was inconceivable an independent Scotland would secure an EU budget rebate, as currently enjoyed by the UK.
They dismissed SNP claims an independent Scotland could join the EU seamlessly, and on improved terms, as they unveiled Whitehall's latest Scotland Analysis paper on the consequences of a Yes vote in September's referendum.
The 120-page study suggested EU membership could cost Scots households up to the equivalent of £210 per year if the country left the UK. Figures suggested an independent Scotland would have to pay between £1.9 billion and £3.8bn over and above its present share of UK contributions, over the 2014 to 2020 EU budget period.
The £1.9bn figure - equivalent to £750 per household - was based on a "most optimistic" case, the paper said, accepting Scottish Government claims an independent Scotland would secure an extra £850 million in agricultural subsidies. The £3.8bn - equivalent to £1470 per household - was a worst-case scenario, under which farm payments would fall by just over £1bn.
Mr Alexander told an invited audience of business leaders in Glasgow: "What this means for Scottish families is that over the next seven years continuing as part of the United Kingdom will save them at least £750 per household, possibly climbing to £1470 per household.
"So, as part of the UK we Scots pay less, and we get more out of our EU membership."
The Whitehall paper on EU and international issues, the ninth in the Scotland Analysis series, said SNP claims an independent Scotland could take a share of the UK's £3bn annual rebate were based on a misunderstanding.
It said the UK rebate would be cut to reflect the reduced size of the country in the event of Scottish independence, removing a "Scottish share".
Instead, the paper warned, an independent Scotland would end up having to contribute nearly £600m over the seven-year budget period towards the UK's rebate.
Mr Alexander added: "The bottom line is this: Scotland outside of the UK would have to negotiate its own way back into the European Union, and as such its terms of membership would be entirely different to those we currently enjoy. Scotland would be a net contributor to the EU, it would pay more than it would get back."
Foreign Secretary Mr Hague said negotiating EU membership terms was "unlikely to be as easy as the Scottish Government makes out".
He said an independent Scotland would have to negotiate hard and expend considerable "political capital" to resist pressure to join the euro single currency and the Schengen zone, the free travel area covering most of Europe apart from Britain and Ireland.
He also argued Scotland benefits from the UK's substantial network of diplomatic, consular and business support around the globe. He said: "The Scottish Government is offering a fraction of what Scotland already has. There are grave risks to independence."
He insisted it was a positive choice to support Scotland remaining in the UK.
Nicola Sturgeon, Deputy First Minister, said: "The fact is Scotland would receive £850m more in farm payments if we were an independent member of the EU."
She added: "William Hague is the latest in a series of Coalition ministers making flying visits to Scotland to lecture us on the dangers of independence. Yet none of them is actually prepared to debate - openly and directly - with Scottish ministers.
"More than ever Scotland needs direct representation in Europe so we can protect and promote Scotland's interests."