jura2 i think you are absolutely correct to a very considerable extent. That was probably uppermost in the minds of those with lots of money, particularly those with offshore bank accounts and the funds to pay high-powered accountancy firms to manipulate their figures and the existing legal loopholes in tax law. They certainly led the way and urged the leave vote.
However, there were undoubtedly many who voted leave whose financial position was in a far less comfortable place. Some, perhaps, fully understood the workings of the EU, Byzantine though they are, who still believed leaving was the better option. There were others who were deluded by misleading statements about sovereignty, which was never lost to the UK, as well as Boris's "straight bananas rule" and other lying nonsense. I think the "promised" extra money to the NHS was an immense lure as it is so dear to the hearts of everyone and has suffered a severe lack of funds for many years under Tory false austerity.
I think there are also those who believe that the UK is overcrowded and cannot take any more EU workers, immigrants and refugees, although, perhaps, they didn't calculate that many of those already in the country in vital jobs might decide to leave in the event of Brexit. Then there were those who are outright racists who seem to think that all the foreigners – especially those with brown or black skins, who wore turbans or saris – would be sent "home". Ditto about those from the EU who came to work – hugely reliably – as plumbers, kitchen fitters, bathroom fitters, carpenters and other tradesmen of whom there are not enough.