Would the following scenario work:

1) Buy several fully refundable businessclass tickets on your airline of choice.
2) Buy one coach class ticket that gives you the right to be upgraded, either based on your status with your airline of choice or as a result of fare class.
3) Ask for an upgrade during coach class booking or get yourself on the upgrade list.
4) A few hours before departure cancel the whole lot of refundable businessclass tickets, effectively opening up seats for upgrades.

DONE!