I want to rebuy for the LMS since this will be the last round before the fee doubles up, but I don't think it's worth it assuming i'll miss out on the points from the third and fourth rounds and start with five points.
Are you sure you are allowed to rebuy?
As far as I know, only those people that lost in round 4 are now eligible to rebuy. Those people that were eliminated in the previous rounds have eliminated and they can't continue in LMS.