landof4x's numbers are spot on.
12 months ago an annual retention of 18K for F/O's and 30K for Captains was put to the REX CP. Cost $7.25 a ticket. And that was only if every pilot stayed to collect! As some pilots would have left anyway, REX could either adjust the levy downwards or if left the same, they would have actually made money! Rex would not however have lost their critical Check and training and senior Captains, all for $7.25 a ticket!!
I'm afraid now it has become much more difficult. If you take landof4x's $75K for F/O's & $125K for Capts, restructure it to $60K base + 15K annual retention for F/O's and $100K base and 25K annual retention for Capts, then REX's crewing problems would see a definite reverse. The situation is now that serious, it would take something along those lines to save the company.
And before anyone cries it is too high, just keep your eye on what QFLink will be offering in the very near future. DEC's are definitely on the way, and you don't have to be a rocket scientist to figure out where they are going to come from!