We believe the going rate for a couple would normally be around the $200 per day for short term.
I would think that maybe something around $1000 per week for longer terms. Maybe you could come up with an incentive bonus if you achieve a higher than expected occupancy.
This comes with its problems as if this is not achievable, it could lead to managers losing interest, but I think that this would show in their performance and attitude.
Whilst, like us, you may want to keep most things close to your chest,you may like the idea of getting managers involved in basic emails and bookwork to keep them enthused.
Remember one thing, It is Your Business and if they are not working out, cut your losses before it drives you to despair,
Many times we have a false belief that our staff are great, but don't let them rule the roost.