If your main worry about being in the EU is the amount that immigrants receive in benefits, then you may be interested in this from the Telegraph:
'The data from the Department for Work and Pensions (DWP) and HMRC, also show that the majority of welfare recipients are British.
In 2014, 4.9 million (92.6 per cent) working age benefit claimants were British while only 131,000 (2.5 per cent) were EU nationals. The number of recipients from outside of the UK — but not from the EU — was 264,000 (five per cent).
Likewise, in the latest data from 2013 for those tax credits, 3.9 million (84.8 per cent) families receiving the benefits were British citizens, 302,000 (6.4 per cent) were EU citizens and 413,000 (8.8 per cent) were from outside of the UK.'
Stopping benefit payments is going to make practically no difference to the amount of money that is paid out in the UK