I just booked a midi star alliance 26,000 mile RTW for $2300AUD.
My itinerary is:
MEL->SYD->LAX->LAS->PHL->LHR->SIN->DPS->SIN->MEL
For a grand total of 25,968 miles
.
I was pretty lucky, because anything over and I would have had to have spent an extra $400 on upgrading my ticket.
How close you have been?