37,500 avios is correct for business. First would be 50,000 avios.

What award chart are you looking at? BA does not publish an award chart, so presumably you are referring to an out of date award chart. The rates were changed over a year ago.

For an up to date chart refer to the 'Other airlines' on post #3: http://www.flyertalk.com/forum/briti...os-2016-a.html