Ask if they will pay for the rating, then take 10% out of your pay every month until paid off.
If you do that, you're only supporting management's poor decision-making and practices.
The costs of initial and recurrent training are miniscule in comparison to the acquisition and yearly budget of a bizjet. Your awareness of these basic economic facts should be pointed out at your next meeting, hopefully with the CP and HR both in attendance. Should the fueler pay your company for the 'privilege' of putting in jet-a? Does the caterer do the same? Does your waitstaff at lunch drop off 10% of your lunch bill for the 'treat' of serving you?
I had something similar happen years ago. The pilots stood together, refused to accept the proposal, and management capitulated. The CP was let go soon after.