Yes! That would allow a manual report.
A great first step would be having it as an export field on Sales, not the sales ledger and it would be good if you could do this. (not the sales ledger because of the additional complication that you have both rows containing invoice row items and rows with invoice totals which you would have to separate first)
In case it is not clear what this then means is that that the data would need to be dumped on to a spreadsheet. sorted by country. Then columns added which would cumulate the net cost while the country does not change. Then another column created which would only pull out those cumulated figures where the next row is a different country which would be the cumulated total for each countries and this reported.
The formula for this are known to us because we have to do exactly the same, but with date ranges iather than country in order to produce a payables report - something else that is a basic reporting requirement,. It would be really good if you could get a grip of basic reporting and something that would more than pay for itself by attracting more customers. I dont know what market research you have done but I suspect the reason for trialists that dont convert is down to your poor reporting capabilities and the inability to customise what you do chose to export . (rant over!)