Those are the current limits they are operating under before...

Those are the current limits they are operating under before financial verification is required. Considering Austrac does not look at single bank deposits below 10k, it is probably a reasonable number to prevent money laundering. If those limits are kept then the transition to cashless should result in minimal revenue loss from where the business is currently. Only the costs of the transition. Considering the Sydney business is basically break even in terms of profitability despite the hotel and restaurants it runs I would say that keeping the 5k limit is necessary to keep the business break even.