Private equity firms running the ruler over Australian brewer Foster's wine business could baulk as the Aussie dollar's surge to 28-year highs has raised the unit's price tag by 20 per cent since a sale was first proposed. Private equity managers say banks may also be less willing to lend for a cyclical asset dependent on fickle consumers, compared with the defensive credentials of hospitals operator Healthscope - sold in July for $2 billion in Australia's largest private equity buyout since the boom.