Points to consider, page-6

On looking at the exercise price formula (original prospectus) is would appear that if the VWAP of VXL stays at 28c then the exercise price of VXLO will be modified by the formula:

New Exercise price = O – E*(P – (S + D))/(N + 1)

Where (current value in brackets)
O= the old Exercise Price of the Option (currently 25c)
E=the number of underlying Shares into which one Option is exercisable (1)
P=the volume weighted average price per Share recorded on the stock market of ASX during the 5 trading days immediately preceding the ex rights date or ex-entitlements date (28c)
S= the subscription price for a Share under the pro rata issue (29c)
D= the dividend due but not yet paid on existing underlying Shares (except those to be issued under the pro rata issue) (0)
N=the number of Shares with rights or entitlements that must be held to receive a right to one new Share (0)

Plugging in the current numbers then the exercise price will be revised to 26c. In this context you are .5 cent better buying on market than in the RI; however if you are also a VXLO holder you are better off buying in the RI due to being penalized by the increase in the VXLO exercise price. The higher the VWAP goes the better for VXLO holders as the exercise price will be reduced (i.e is the VWAP goes back to 36c then the VXLO exercise price goes down to 18c).