The 500k bid is a prop to stop the bots grinding the sp down as there is virtually nothing on the bid side, i.e. a couple of days ago the total volume for the day was 1 share!...but it dropped the sp by about 4%.
IF they move to compulsory aquisition, you can bet it will be based on an average of vwap imho, which won't be 55c or anything near it.